Thirst

"Let no one pray for me."

Thirst is a 2009 horror/drama film directed by Park Chan-wook, best known for Joint Security Area and his Vengeance Trilogy. The film is a very loose adaptation of the novel Therese Raquin written by Émile Zola.

The film follows Sang-hyun, a Korean Catholic priest who contracts vampirism during a medical experiment. Still motivated by his strict religious upbringing, Sang-hyun commits himself to feeding through non-harmful means. Soon, however, he bows to his increasingly powerful urges and becomes infatuated with Tae-ju, the Cinderella-like wife of a childhood acquaintance. Sang-hyun soon begins making moral concessions to get closer to Tae-ju, who turns out to be much more dangerous than he could have imagined.

Tropes used in Thirst include:

Above Good and Evil: Unlike Sang-hyun, Tae-ju takes this attitude to vampirism, comparing a vampire killing a human to a fox killing a chicken.
And I Must Scream: Lady Ra
Beware the Nice Ones: Sang-hyun.
Black Comedy: There are a few moments of dark humor, like when Sang-hyun and Tae-ju are arguing over whether they should go through with their plan of murdering Kang-woo. While Kang-woo is sitting right next to them, meekly suggesting that they don't.
Blood From the Mouth:
- Blood pours out of Sang-hyun's mouth as he plays the flute just before he dies of the EV disease. Of course, he doesn't stay dead. It happens again later when he experiences another resurgence of the disease.
- Tae-ju's mouth pours blood when Sang-hyun crushes her throat. He licks the blood off of her chest until deciding to turn her.
Broken Pedestal: Sang-hyun is horrified and repulsed when his mentor, a blind old priest, begs to be turned so that he can regain his sight. This leads him to reject both his faith and the priesthood.
Cue the Sun
Destructive Romance: Between Sang-hyun and Tae-ju.
Femme Fatale: Tae-ju, who seduces Sang-hyun, convinces him to murder her husband and turn her into a vampire, then turns into a gleeful killer.
Fingore: When Sang-Hyun volunteers for the medical study he suffers the effects of the Emmanuel Virus, one of which is his fingernails falling out.
Foot Focus: Tae-ju's feet are a "running" theme. She sprints barefoot through the streets at night for a brief moment of escape from her mundane life, growing thick calluses. Sang-hyun's first romantic action towards her is to physically place her in his shoes. He also pays particular attention to her feet during their lovemaking sessions. Sang-hyun's shoes get a bittersweet callback at the end of the film.
Friendly Neighborhood Vampire: Sang-hyun does his best not to kill anyone. He takes blood from a comatose patient he believes would have given his blood freely to the hungry. He also provides peaceful suicides.
Hemo-Erotic: When Sang-hyun is alone with Tae-ju, he wants to have sex with her and wants to drink her blood - and does both, at the same time. She wonders out loud if it is weird that she enjoys it.
I Hate You, Vampire Dad: The two main characters experience quite a lot of this, though their relationship was fraying well before Tae-ju becomes a vampire.
May-December Romance: Perhaps not intentional on the director's part, but the actors playing Sang-hyun and Tae-ju are twenty years apart.
My Beloved Smother: Lady Ra dotes on Kang-woo, who always seems to be ill.
Not So Different: After Sang-hyun confronts Tae-ju about framing Kang-woo so Sang-hyun will kill him, Tae-ju claims that Sang-hyun would have gone through with it any way
Our Vampires Are Different: Vampire blood can heal your infirmities and illnesses, but only so long as you're full of it. Vampires don't grow fangs, but they can still suck blood from bite wounds. They're super-strong and almost totally immune to damage, but do have the typical weakness to sunlight. Sang-hyun also briefly flies.
Riddle for the Ages: Sang-hyun seems to believe that he got a transfusion of vampire blood in Africa. How vampire blood came to be in an African hospital is never explained, nor does Sang-hyun make any attempt to find out.
Stop Worshipping Me!: Sang-hyun becomes famous as "the bandaged saint" after miraculously surviving EV. A small group of followers camp outside his monastery, to his great annoyance. In the end he pretends to try to rape one of them so that they'll abandon their vigil.
Suicide by Sunlight
Wicked Stepmother: A subversion. Lady Ra is tough on Tae-ju, but during a drinking session she reveals that she does care about Tae-ju and plans to put the family business in her name. Tae-ju makes Sang-hyun believe that her family is much worse than they really are.