The Pilfered Princess

An erotic fantasy novella written for the Usenet newsgroup alt.sex.stories by an author using the name "A Strange Geek", The Pilfered Princess is a rather unusual take on fantasy literature, shot through with dry humor and a lot of Genre Savviness. Princess Sarah has been kidnapped by the Dark Lord Mallevelus in hopes that her father, the Good King Benificus, will drop the purity barrier that protects the Kingdom of Light so that he can invade and take over the kingdom. However, for reasons that quickly become clear, and despite the chagrin of his guardian angel Joy, Benificus really doesn't care about the kidnapping...

The story can be read here (assume it's NSFW).

Tropes used in The Pilfered Princess include:

Anything That Moves: Princess Sarah, whose promiscuity is what gets her kidnapped in the first place.
Aren't You Going to Ravish Me?: Sarah to Inferno, almost constantly.
Card-Carrying Villain: Mallevelus, with a whole battery of Stock Evil Overlord Tactics to go with it.
Cool and Unusual Punishment: The villains eventually figure out a way to get around Princess Sarah being Too Kinky to Torture: they put her in a chastity belt.
Dangerously Genre Savvy: Sarah.
Dramatic Thunder: Mallevelus has a spell that causes this.
Deadpan Snarker: Inferno, the incubus put in charge of Sarah's torture, who generally finds his master tedious at best.
Face Heel Turn: Princess Sarah, sort of. She kills Mallevelus with his own weapon, neutralizes the Army of Light by destroying their biggest weapon, takes Mallevelus' place as the Dark Mistress, and corrupts Joy from guardian angel to willing sex slave. However, her turn comes with a heavy dose of Dark Is Not Evil, making it somewhat of a subversion.
Horny Devil: Inferno the Incubus.
Lawful Stupid: Joy, the Kingdom of Light's guardian angel, whose strict vision of moral purity annoys even her master, King Benificus. She gets better.
Meaningful Name: Benificus, Mallevelus, and Inferno. Inverted with Joy, who is obnoxiously uptight and priggish. Until Sarah gets to her.
Only Sane Man: Inferno.
Prince Charming: Smidlar, the King's Champion.
Punch Clock Villain: Inferno, who has no real loyalty to speak of to the inept Mallevelus.
Running Gag: Nobody takes the notion of Sarah being 'pure' seriously. Not even the animals.
Too Dumb to Live: Mallevelus, who's so concerned with the trappings of evil overlordship that he neglects to actually pay attention to important information or do anything really useful at all.
Too Kinky to Torture: Sarah annoys her torturer by orgasming during a torture session, and spends the entire story begging Inferno to "rape" her. Because, frankly, the Dark Lord's ogres, trolls and other assorted underlings just aren't that good at the whole sex thing. Shades into "It's Not Rape If You Enjoyed It".
Wrong Genre Savvy: Smidlar, who is informed on practically every trap and cliche that could possibly befall a King's Champion, but misses the fact that everyone thinks he's on a fool's errand. And that it's a parody. And he winds up killed when he tries to claim his prize as a result.