Covert Pervert

"Haruna: (to Nodoka) I never expected you to come up with something so naughty!"

- Mahou Sensei Negima

Uncharacteristically suggestive comments and thoughts from a character usually considered pure and innocent. Sometimes this is played straight and shows that a character is mature or smart enough to notice subtle themes their friends don't. Most of the time it's a trait given to a shy character to show they're not quite as mousy and meek as we think. Usually cued by fantasy segues becoming more and more lewd.

This will always be fiercely denied by the character, especially if they're cantankerous and dismissive. The more comedic princess-like types often get this too, until it turns into a more overt Running Gag.

Note that the title refers to covertness in the figurative sense, not the literal. This trope is also Truth in Television -- you know who you are. Don't say it, otherwise you won't be one anymore. If the Covert Pervert is outed they may be subject to a girl getting set to Pervert Revenge Mode or even an Unprovoked Pervert Payback.

Probably due to the often seen Double Standard that women should not show their sexuality openly, over half of the examples of this trope are female, while perverted male characters tend to be obvious.

Anime & Manga
"Setsuna: (beating herself up for her overactive imagination) This isn't a future! This is just a delusion! What's wrong with me! This isn't right! I'm bad! I'm perverted!"
 * Ami Mizuno/Mercury in Sailor Moon sometimes has shades of this, with the excuse that she really is the smartest of all the girls. Despite horrible reactions to love letters, she was worldly enough to assume alien-turned-villain Fiore was actually attracted to Usagi's boyfriend. The joke gained more fodder with the introduction of Haruka and Michiru, where Ami is the only character not completely unfazed by the situation and quite frankly understands the nature of their relationship. Similarly, a much later gag from Stars with a handsome young man and a short towel has all the girls shocked... save Ami, who seems to be peeking between her face-covering hands. And let's not forget she's got very exclusive Starlight fan stuff that the other girls (much more open Starlight fangirls) don't...
 * Rei Hino/Mars is one too. In the anime, she's in possession of rather saucy mangas, magazines and doujinshis involving Cross Dressers and is very flustered when Usagi finds them.
 * The otherwise motherly and elegant Cherry in Saber Marionette J fell victim to these, with her embellished daydreams about Otaru becoming increasingly lewd over time, sometimes ending in an ecstatic pile of Squee right in front of a very confused and creeped-out Otaru. Hanagata did the same towards Otaru and at least once in Saber Marionette J Again, Luchs did towards Faust.
 * Yuri Zahard lusts over Baam to the extent that she gets hilarious Nosebleeds.
 * Shinobu in Love Hina. Too bad people always point the blame to Keitaro whenever she gets a perverted thought in her head.
 * Same goes for her Expy Nodoka in Mahou Sensei Negima, a mousy Shrinking Violet who keeps surprising everyone in the cast with her boldness, both as an adventurer and in romance. For example, at one point she discovers that she's stuck in a Love Triangle with her teacher and her best friend Yue. The first solution she comes up with?
 * A more subtle example is Fate. Yes, THAT Fate. He will dress up his Amazon Brigade in Meido clothes whenever he can (and does the same to  at some point), and when he captures , he puts her in a really skimpy gown.
 * Oh, Setsuna Sakurazaki. We can let the fact that she pulled a Groin Attack on a 10-year-old pass because she mistook him for an enemy, but not how her "perfect world"  includes her crush and charge Konoka in a Naked Apron. And then there's her daydream about her ideal future, where she shares a hotel suite with Konoka, who approaches her while clad only in a Modesty Towel and proposes that it's about time they have a True Pactio (read: sex).

"Kaede: My first kiss...I'm nervous.
 * Also Kaede. Her pactio kiss involves a look that can best be described as predatory.

Negi: You don't look nervous..."

"Someone: Oh ho? Negi-kun's secretary, eh? Sounds nice.
 * Not to mention that she held that kiss for a few panels and her reply to Kamo telling her the pactio was complete was "Ohh...is that so" while giving Negi in an obviously deliberate Marshmallow Hell. Negi's hand is also blatantly groping her and the sound effect has a heart next to it. She may be a ninja but this is one area she ain't too subtle in.
 * And now Chachamaru of all people:

Chachamaru: (daydreaming) Yes...

Someone: So... he'll wind you up every day?

Chachamaru: (still daydreaming) Yeah..."

"Mizuki: I think Minami-chan will use this chance to touch Akihisa-kun's chest and butt...that's too sneaky...”
 * Lucia Nanami in Mermaid Melody Pichi Pichi Pitch gets blushy and angry at the more overtly dirty-minded Hanon, but take a look inside her mind...
 * Haruki Hanai from School Rumble tries his best to be a very moral and strict character, but he is human with his own perverted moments and thoughts.
 * Kareha from Shuffle. Only covert in that she doesn't say out loud what she's imagining. However, whenever a situation that could be construed as romantic or perverted presents itself, she will Squee and glow.
 * Nori in Rozen Maiden is a gracious, kind older sister to the horribly antisocial protagonist Jun. You'd think she's just patient, but she also talks in her sleep, and says some really odd things.
 * Mirei Shizuoka of Umisho is viewed by her peers as being pure, innocent and shy. Yet she wears lingerie that's extremely sexy beneath her clothes, has expressed interest in seeing the bodies of her male team-mates on the swimming team, once suspected Kaname and Amuro of doing This and That, and has expressed interest in buying a large, phallic antique.
 * Tsuyuri from Doujin Work acts like an Emotionless Girl most of the time and has a very youthful, sweet appearance. Still, she is one of the most perverted characters around, as evidenced by the extremely sadistic erotic Doujinshi she produces. She also projects her fantasies on her friend Najimi, who she firmly believes to be a masochist.
 * Yoshika from Strike Witches develops a thing for big breasts, probably because she practically becomes surrounded by an Amazon Brigade consisting of scantily clad, buxom young ladies?her best friend first and foremost. Of course there is nothing wrong with that in and of itself, but Yoshika tends to act on her attraction at the most awkward moments.
 * Louise of Zero no Tsukaima, especially in the light novels. She beats up Saito at the first sign of his pervertedness, yet whenever we are shown her fantasies, it's rather... saucy. At one point she attacks a large crowd for waking her up from a dream of her and Saito that was "just getting to the good part".
 * To someone who didn't know better, Yuria of Yuria 100 Shiki would appear to be a Covert Pervert. In fact, she is a Ridiculously Human Robot specifically programmed to be such and one of her features is she will instantly imagine the indecent side of anything.
 * Ken Nakajima from You're Under Arrest. So much that he's nicknamed "Mr. Nosebleed" by one of his co-workers.
 * Asami of My Wife Is a High School Girl constantly feels frustrated by the fact that she can't get it on with her teacher husband, thanks to her father's forcing a "Jail Bait Wait" on the couple.
 * Tomoyo Dadiouji in Cardcaptor Sakura is calm, mature and refined in most situations, she also has a passion for dressing Sakura, the perpetually oblivious target of her affections, in a vast array of fetish-tastic outfits while she records her... and watching aforementioned recordings repeatedly... alone...
 * Darker Than Black has an OVA that reveals that resident Yaoi Fangirl Kiko has introduced Yin, of all people, to the world of slash fanfic. Really dirty slash fanfic, at least one of which involved doing something unmentionable with an elephant.
 * Mai, who works for Pilaf in Dragon Ball. When Pilaf said that they needed to find the "balls", Mai simply responded, "Perhaps between that man's legs." Pilaf and Shu didn't take it well.
 * Takeo Takakura in Magic Users Club is plagued by his own perverted thoughts, usually directed at his female club members.
 * In Soul Eater after wandering around in the Lust chapter of the Book of Eibon (just go with me on this one...) Tsubaki Natsukasa and Liz Thompson remain as males a bit longer than they should...
 * Yukinari of Girls Bravo is rather reluctant to be around girls mostly because of how he's been bullied and beat up by girls his whole life. He also gets incredibly nervous when Lisa, who is infatuated with him, constantly tries to abduct and seduce him. However, he got a nosebleed when he saw Miharu in a blouse and panties, and one episode reveals that he keeps porn under his bed.
 * In Goshuushou Sama Ninomiya Kun the innocent looking Mayu is actually a Yaoi Fangirl, who writes her own yaoi manga, and Reika can actually be incredibly perverted, which she hides behind a Tsundere facade and hits Shungo if she feels he's acting perverted.
 * Mafuyu from Seitokai no Ichizon. She has a shy personality and looks innocent but she is a huge yaoi fangirl who fantasizes pairing Ken romantically with a boy named Nakameguro. In fact, when it comes to yaoi, Mafuyu can actually be just as perverted, if not worse, than Ken.
 * Whether Shinji Ikari is this or actually a genuine Chaste Hero whose sexual repression occasionally lapses is up for interpretation.
 * Several characters in Axis Powers Hetalia.
 * England seems like a bit of prude until you get him drunk or learn about his people's sexual records;
 * Japan has monologued before about the superiority of 2D over 3D:;
 * Germany seems to have a thing for bondage and possibly bestiality (according to Italy);
 * Japan's "little brother" Hong Kong loves to make porny artwork despite China's protests and doesn't seem to regret it one bit;
 * Hungary will beat up you and your entire army with her Frying Pan of Doom if you harm her husband Austria... unless you happen to be a good-looking young man attempting to molest him.
 * Seto no Hanayome episode 15. When the class president says Nagasumi has become more manly, two flashbacks are shown of him naked.
 * In Eyeshield 21, when Sena, Monta, Mamori, and Suzuna visit a bath house in order to talk to Kakei of the Kyoshin Poseidons, Mizumachi's attempts at peeping on the girls' side lead to the normally shy and quiet Sena having a vision of Suzuna, naked except for a towel held against her front.
 * Luca in Macross Frontier looks younger than he really is, so when Sheryl suddenly calls Alto her slave in public, he immediately [[media:slavehime.jpg|imagines Alto tied up with Sheryl standing over him in a dominatrix outfit]]. Of course it doesn't help when Sheryl is always Playing to The Fetishes. It also doesn't help when Luca's crush, Nanase, is the most buxom character on the show.
 * The Great Guardians saga of Ikki Tousen shows us just how dirty Kanu Unchou's mind really is.
 * Kouchu Kanshou is also reveled to be one as well.
 * Koukin is hinted to be one of these, though in his defense he doesn't always seek it out.
 * Yuuki Rito of To Love Ru is one, which a bit of a surprise considering he is Allergic to Love to a small degree. First it began with the few and far between Imagine Spots centered solely around Haruna, before branching out a bit to include others. By Darkness he seems to be strangely fine with the 'Harem Plan' and dreaming of naked girls in the bath.
 * Star Driver's Wako is one -- or at least would be if her imagination wasn't on display for everyone to see.
 * Karakuridouji Ultimo has Yaoi Fangirl Kiyose, who blushes when she sees her two friends Yamato and Rune together. In Yamato's case, it's annoying, in Rune's case, she was right.
 * Akikan has Najimi.
 * In Ranma One Half, perverts tend to be more obvious then anything -- Happosai and Tatewaki Kuno most prominently. However, there are subtler displays of perversion. Ukyo Kuonji is normally the most normal-seeming female of the fiancees, with a record that includes slapping Ranma for flashing her breasts to Ryoga and whacking him for calling her cute/asking if she loved him (admittedly, she had been attacking him just before). However, when Genma (in the manga) reveals he has a nude photo of Ranma, Ukyo begs him to let her have it and is shown practically drooling over what she can see of it.
 * While whether he has perverse intentions or not is endlessly fought over, Ryoga Hibiki is a more literal interpretation of this, in that his P-chan form allows him to be taken to Akane's bed, fed off her plate, held in her lap, cuddled to her breasts and even kissed on the nose by her at least once. All without her having any idea that Ryoga and her pet pig are the same being.
 * Speaking of Akane, for being such a prudish girl who freaks out at the mere sight of a naked man, she is also the quickest person of the cast to see the perverted potential in just about any whacky set of hijinks. Especially if it involves Ranma. A first-rate example is when Kuno was about to ask for a wish to a magical rock: while she and Ranma discussed it, Akane imagined Kuno asking for female!Ranma to love him, and immediately came up with the Imagine Spot of Kuno taking advantage of this to rape Ranko on the spot. She ends up giving a Big No.
 * There's also there's her Rescue Romance fantasy from the manga, including "Glad to Be Alive" Sex and all.
 * Ranma counts too. He's always ready to flash his chest to win a fight.
 * Ranma's not a pervert, but rather a good strategist. He's a guy, therefore he knows how guys will react to women and their bodies. He also likes using whatever he can to his advantage, so his good looks, knowledge of how the male mind works, and own shamelessness are all tools to him. (In the manga, at least.)
 * Of all people in Bleach, we have Retsu Unohana as this. In Bleach on the Beach, her Number Two Isane was freaking out over a skimpy one-piece her sister, Kiyone, wanted her to wear, which was amusing enough. Unohana decides to intervene... This staid, primly-dressed, motherly woman takes Kiyone's side. And then reveals her own swimsuit... which is even skimpier.
 * Sui-Feng. Holy SHIT, Sui-Feng. Who'd say that the coldest, more ruthless Tsundere in the Gotei is such a Yoruichi fangirl? Not to mention there's how, in an omake, she pinned Ukitake to a tree with kunai so people could take photos of him. And this was done on behalf of Kiyone who has a major crush on Ukitake, meaning Kiyone's an example of this trope as well.
 * When Ichigo tells Rangiku she can't stay at his place, she lets her skirt ride up and begins unbuttoning her blouse. Ichigo slaps his hands over his eyes and protests aggressively, telling her off... while all the time peeking at her body through his partially opened fingers.
 * Aizen can measure your bust, waist, and thigh sizes with his eyes. Enough said.
 * In the Girls Love manga Husky and Medley, Medley is surprised to learn during an after-school encounter in an empty classroom that Husky, who everyone thinks of as the perfect strait-laced schoolgirl, actually has a bit of a dominance kink. After Husky holds Medley up against a wall in an embarrassing position while kissing her, Medley reports to 2ch that "this was the day I became a masochist".
 * Mio in Nichijou has moments of this. Throughout the episodes, she has to chase down her friend Yuko to get back her notebook after belatedly remembering she had drawn a naughty picture of the guy she likes in it, she gets in a drawing competition with Yuko and ends up getting carried away. Most recently she ends up attacking a police officer, an old man, Yuko, and a goat when they all catch sight of her drawings in her desperation to get them back.
 * Ebisu in Naruto is a major example of this. He always berates Naruto for using his Sexy no Jutsu technique (calling it indecent) but is nonetheless consistently "defeated" by it. Naruto even refers to him as a "closet perv".
 * Sakura is another example. When Konohamaru showed off how he had learned the Sexy no Jutsu, Sakura got angry and called him out... but then he showed his "counterattack" by creating a Ho Yay Sexy no Jutsu with naked Sasuke and Sai. Sakura promptly had a nosebleed.
 * Fairy Tail has actually several examples of this. The most prominent would definitely be Erza with all her weird, often quite Stripperiffic armors, of which she states she prefers the Bunny Girl. Later, she buys a "seduction armor" which is essentially several types of Fetish Fuel packed into one piece of clothing. In the Fairy Hills omake, Levy also mentions that she apparently likes "sexy books", and when Natsu and Gray looks through Lucy's chest of drawers to find her underwear, they easily make an interested Erza join them.
 * Happy has one single and very small, but quite noteworthy here. While Lucy and aforementioned Erza defeat most of their opponents in the panel in the middle row with normal attacks, Happy apparently defeats his by ripping off his clothes on the lower body.
 * Makise Kurisu of Steins;Gate picks up on Daru's innuendos, which he the points out each time much to her embarrassment.
 * The hyperactive, flustery Cloudcuckoolander Oshiroi from Ben-To. When Satou asks her if she wants to join the Dogs, she thinks he wants to know if she wants to get gangbanged. She doesn't reject the idea outright, just says she'd prefer her first time to be one-on-one.
 * Mizuki Himeji from Baka to Test to Shoukanjuu certainly qualifies, during an event were the summoned being spoke the characters true feelings Himeji's confesed to have thought "weird thing" when the other were talking about ecchi things.
 * Also this from volume 7 of the novel:

Minami: Wh, what are you saying, Mizuki! How can I do such a thing—eh, what? What did you just say? Touching...Mizuki, what were you talking about...”

Mizuki: Ah! No, nothing! I'm not talking about touching him sneakily. Th, that...I'm just talking about improving the relationship with Akihisa-kun. I just said it wrongly!”

Minami: Mizuki..what were you planning to do to Aki...”"

"Dark!Momoka: This isn't just a confession... you're gonna skip straight to @#$%! Go, Momoka!"
 * Yuu Narukami aka the Male Protagonist in Persona 4 The Animation. In the original game this was more optional since you, as the player, got to choose whether he was a pervert or not; in the anime, however, Narukami makes this face upon seeing Shadow Yukiko in the Midnight Channel, and then says "I wish I had taped it." And later, when Shadow Kanji and his minions have Yukiko and Chie covered in slime, Yosuke asks him if he does have a camera, and he says "Dammit, no!"
 * Because Yu is also The Stoic, he almost always gets away with making perverted quips around his female friends, unlike Yosuke who tends to be a lot more energetic.
 * Momoka Nishizawa from Keroro Gunso may be one. When Mois gets "scary story" (kuaidan) mixed up with "dirty story" (waidan) in one chapter, Fuyuki and Natsumi listen to her story red-faced, too embarrassed to comment. Momoka's blushing too, but is also listening intently, and even tells her "Yes, yes, go on!" In another chapter, Momoka tries to get Fuyuki to indulge in some Intimate Healing, much to the delight of her "dark side".


 * The normally Chaste Hero Link has shades of this in a manga adaptation of Zelda II the Adventure of Link. When a spirit guide Zelda tells him that he can use magic, his first thought is using it to remove her clothes.

Fan Works

 * Nagato and Hanyuu are this in Kyon: Big Damn Hero, spending part of the time when they were watching Kyon 'enjoying the view'.

Literature

 * In the book Behaving Bradley, a high school boy gets nicknamed "Microdick" after the other boys see him putting his bathing suit on in the locker room. Hopie, a sweet, naive girl, asks the main character what the nickname means, and he tells her it's because the boy wants to be a disc jockey and use a microphone. She responds "Oh, I thought it was something about his penis."
 * Wendy Varovitch.
 * Shin-tsu, oh so very much.

Live Action TV
""Oh, right. Me and Oz play "Mistress Of Pain" every night"
 * In Buffy the Vampire Slayer, occasional hints are given that Willow is actually one, like her "Everyone's getting spanked but me." comment (and the accidental ogling of Dawn (the Dawn part was the accident, not the ogling) that one time).

"Did anyone else go to a scary visual place?""


 * She suggests that Buffy might become a transexual after being infected by a demon.
 * Her girlfriend Tara seems to be the same.
 * This is the most obvious character trait of Tobias from Arrested Development, who never seems to consciously think or care about sex at all.
 * There's a rather startling scene in Pushing Daisies where Chuck, in an attempt to prove that she's not as sheltered as she seems, talks about her aunt's collection of erotica.
 * Mindy from Mork and Mindy. In the pilot, she asks Mork to test his voice by reading from a book she has. Turns out it's a steamy romance novel. And later in the series when it's revealed that Orkan ears unscrew, she says "Gee, I'm afraid of what else comes off!".
 * Phoebe from Friends was initially like this before they used it so much that it became less covert and more just part of her character that she was the kinky, frequently sharp tongued and kind of mean, one.
 * The ICarly trio want to hire an intern to help run their show. Sam wants to know if the intern will scrub her when she's having a shower or bath.
 * Rachel and Emma from Glee. "Push it" was Rachel's idea and Emma informs Rachel that someday not having a gag reflex will be a gift. If you know what she means.
 * Though Firefly has plenty of characters with overt sexuality, the last place one would expect to see such sexual commentary from is the somewhat unhinged yet innocent River. Nonetheless, she gets in the occasional comment that makes it very clear she's paying attention.
 * In the comic Those Left Behind, Wash and Zoe make love on the bridge, and then suddenly have to call everyone else up to the bridge when they find something important. No one says anything as the two are straightening out their clothes... until River blurts out "It stinks like sex in here."
 * Not to mention in Serenity
 * And her "cockney comeon" to Badger.
 * And River doesn't hesitate to bait Jayne into chatting about his "man-parts" - and it doesn't seem to bother her when he does, either.
 * The Doctor Who episode "Amy's Choice" hints the 11th Doctor might be the darker side of this trope.
 * On a much lighter note, Rory, if the 2011 Red Nose Day short is anything to go by. He responded quite well to his wife flirting with herself from the future.
 * Also, the reason everything went wrong in that episode was Amy's fault. Rory was helping the Doctor fix the TARDIS and Amy was wearing a skirt. On a glass floor. Under which was Rory. Rory did apologize, for what it's worth.
 * And Amy owned up immediately to being the ultimate cause, no less.
 * The Tenth Doctor once remarked that a "solid leather" slave drone rather suggested that "someone's got one hell of a fetish."
 * Many instances of Annie on Community doing this. Most noticeably in her stint as Hector the Well Endowed, a D & D chracter, who has to seduce a elf maiden.
 * Dr Chi Park on House. Comes across as mousey and repressed, 95 per cent of the time. The other five per cent she's accusing Dr Adams of wanting to masturbate over her, or casually claiming to have had sex with over thirty guys (which she then admits is a lie; whether the true figure is higher or lower remains unknown).

Video Games

 * A rare non-comedic example of this trope is James in Silent Hill 2, who initially appears to be a relatively normal (if rather dense and insensitive) individual until it's revealed the majority of the twisted abominations that have been attacking him over the course of the game are the personifications of his sexual repression.
 * To give the man some credit, this is Silent Hill! This place gives form to a persons inner conflicts in the most bizarre ways imaginable. While the creatures in the game have a clear sexual theme, there's no indication that he's particularly unusual.
 * Taokaka of Blaz Blue is a childish, innocent-seeming catgirl who's mostly interested in helping her village and eating -- she even sometimes calls characters by cute, childish nicknames, like referring to Nu-13 as the "flappy thing" and Litchi as "Boobie Lady". Except that it later becomes obvious from further dialogue that "Boobie Lady" is not simply a cute nickname based on one two of Litchi's distinguishing features, but that she's downright obsessed with breasts in a seemingly fetishistic way... as seen at one point with the poor 'Average' Tsubaki.
 * When Bang is on the end of a mistaken Skinship Grope from Tao, his reaction suggests him to be one of these as well. And then there's that dream he had in "Teach Me, Miss Litchi"...
 * Fia from Riviera the Promised Land.
 * Normally Merrill not understanding innuendo is a Running Gag in Dragon Age 2, but at one point Anders catches her digging through his spellbooks, looking for 'dirty' spells...
 * Diving deep into the heroines' Cosmos Spheres in the Ar tonelico series reveals their "true" personalities, thoughts, and desires under the masks of being pure, shy, cute, bossy, hotheaded, or whatever in the real world. Given how they present the games, Those heroines have... a lot of unhealthy suggestive things in their minds.
 * The first game gives us  who is normally very soft spoken and unsure of herself. In the latter half of her Cosmosphere, she
 * Apparently this is so dangerous that
 * In Persona 3 Portable, if Akihiko becomes the Female Protagonist's Love Interest, he shows some signs of this. Despite being almost completely Oblivious to Love, when you go up to his room a second time, he's quite eager to "let [their] bodies do the talking".
 * Also MOST suprisingly
 * The "perfect lady" Nera Briscoletti from Dragon Quest V sometimes make an outright sex joke during a party chat.
 * Kenzie Kensington of Saints Row is a not so covert example. When discussing a BDSM club she mentions the safe word she uses there, her crib includes a leather mask and giant Penetrator dildo, and her reply to needing to get laid is that she uses electronics instead.

Visual Novels

 * Most Sono Hanabira ni Kuchizuke wo characters would apply here, but especially Yuuna, Nanami, and Runa. Yuuna is an elegant, much-beloved Ojou...who loves teasing Nanami with her slightly perverted antics, encourages her to call her Onee-Sama, and earns the nickname 'ero otome' meaning 'perverted maiden'. Nanami, for all her getting flustered by Yuuna and as much as she appears like an Ordinary High School Student, finds herself very commonly caught up in sexy daydreams featuring Yuuna that can leave her zoned out for entire minutes. And Runa? She is a confident, happy preschooler who also happens to know more about sex than her adult teacher/lover. (Yeah, just don't try to think about it too much.)
 * Little Busters! has Nishizono Mio, who, upon being invited by Riki to be the manager for their baseball team, more than happily fills in the blanks with her mind when Riki fails to mention the "baseball" part quickly enough.
 * And when the six girls have a Slumber Party and decide to drag Riki over to participate... Yeah.
 * from Katawa Shoujo . Who saw that coming?

Web Comics

 * A rare male example: Onii-chan from Tsunami Channel has shown hints of secretly being a little more "hentai" than he usually acts.
 * Alex/Murfs of Khaos Komix always blushes around his love interest Tom. In the other characters' stories, the impression is that he's blushing because he's shy and embarrassed about his attraction to Tom. In Alex's own story, however, it's revealed that his constant blushing is due to the incredibly dirty thoughts he has about what exactly he'd like to do with Tom.
 * Justin, of El Goonish Shive, of all the main characters, is the first to wonder if using a Transformation gun on a female results in a male form with generous... er... gentlemanly parts. He was gender-bent at the time, but it was still unexpected.
 * And then Sarah of all people has a moment where she can't help but be impressed by her own male form.
 * From Homestuck, Rose sure seemed excited about Karkat's trashy romance novel, and gleefully grabs it away from him.

Web Original

 * "Summoning Sweeties", a Whateley Universe story, reveals that the character of Molly is one of these. Pity her girlfriend.
 * In Touhou a Glimmer of An Outside World, Patchouli owns a large collection of erotica. Koakuma likes to read it, too.
 * Rather prevalent in Touhou fanon is the idea the Koakuma is a succubus. Bound in servitude to Patchouli and made to act as a librarian. The jury's out on which is the bigger pervert.

Western Animation
"Esmeralda: What are you doing?
 * Lois Griffin from Family Guy. This woman seems to have done pretty much anything.
 * From Phineas and Ferb: While it's not exactly sexual, watching Ferb suddenly purr suggestively or start hitting on Isabella has to be a Crowning Moment of Funny. Made even funnier because of it's contrast to Phineas and his relationship to Isabella.
 * Numbuh 3 (Kuki Sanban) of Codename: Kids Next Door.
 * The Hunchback of Notre Dame: Judge Claude Frollo might qualify as this, given how he hides his lustful thoughts behind a self-righteous demeanor. He might alternatively qualify as a subversion, though, given how Esmeralda sees right through him. Consider the scene where he sniffs her hair.

Frollo: I was just imagining a rope around that beautiful neck.

Esmeralda: I know what you're imagining.

Frollo: ... such a clever witch. So typical of your kind to twist the truth, to cloud the mind with unholy thoughts."


 * The Larry 3000 from Time Squad. He has video of Tuddrussel singing in the bathroom wearing only a towel and reads Jackie Collins novels (which are notorious for being highly sexual and sleazy).