Sexually transmitted infections and diseases are a serious thing and there are many ways to get them in real life. In fiction, however, they rarely (if ever) come up. But when they do, it's rarely the "good guys" who get them.
Characters often contract STDs (usually the more dangerous types) as "punishment" if they're villainous. For example, a rapist or murderer who ends up with HIV.
In older works, this is often used as a form of Slut-Shaming. Promiscuous and oftentimes gay characters were "bad", so to punish them they ended up with syphilis, AIDS, or some other sexually transmitted illness. This variation is rarely used anymore, but it can still occasionally pop up.
Contrast with a Tragic AIDS Story, which is a sympathetic portrayal of a character dying of AIDS. Sub-trope to Sexual Karma. See also Good Victims, Bad Victims, But We Used a Condom, and Can't Get Away with Nuthin'.
- In Deep Love, Ayu dies and her friends discover that she died after she contracted AIDS from one of her clients.
- The Chronicles of Wormwood: Jacko (the world's first Australian Pope) is a devout hedonist, regularly seen having sex with nuns. At the end of the first book, his scream of "Full-blown AIDS? FUCK!" can be heard outside the Vatican. This leads directly to the second and third arcs where he wants Jesus to cure him and revenge on Wormwood for preventing that, respectively.
- In Top 10, Andy "Airbag" Soames' years of infidelity comes back to bite him in the ass when he contracts S.T.O.R.M.S., which is essentially AIDS for superheroes.
- The Unfunnies features a sub-plot where Pussywhisker's wife Polly manipulates her husband into letting her cheat on him with other men by having Dr. Despicable amputate his testicles after convincing him he has testicular cancer and making him guilty of being unable to give her a child. Polly ultimately gets punished for her infidelity when she and all the men she slept with die of AIDS.
- Before being retconned to remove all connections from Spawn, Chapel of Youngblood learned that he had been infected with an "inert" version of the HIV virus by Jason Wynn to keep him in line with the threat of somehow turning it on.
- In Death of the Wrong Boy, after spending most of Harry's life neglecting him, favoring his twin brother, and eventually disowning him, it's revealed that James Potter and Sirius Black have contacted many, many STDs due to years of sexual promiscuity.
- In Echoes Of Eternity, a scientist who had been sexually abusing Maria since age five contracted terminal NIDS from her. This isn't revealed until after he had already died, from being shot by Maria's adult friend for trying to rape her rather than because of the illness itself.
- In Temptation: Confessions of a Marriage Counselor, Judith has an affair. After leaving her husband, she turns to drugs and alcohol. Judith ends up contradicting HIV near the end of the film.
- The urban legend of "AIDS Mary", a woman who was raped and infected with AIDS, and went around sleeping with men and infecting them as revenge.
- In Dune: House Atreides, Reverend Mother Mohiam was sent to conceive a daughter with Baron Harkonnen and he drugs and violently rapes her, as revenge she infects him with an STD that ruins his metabolism and reduces him to the hovering blob seen in the original book.
- In the Mr. Robot tie-in novel, Red Wheelbarrow, Elliot tricks Santos into thinking he contracted HIV from raping Carla, a transgender prisoner. It isn't true, but as Santos is a hypochondriac, he spends a good while suffering from the fear of it anyway.
- Discussed in an episode of The Golden Girls in which Rose is being tested for AIDS because of a possibly contaminated blood transfusion. She rants at Blanche that she doesn't know why this is happening to her when she's a good person and that it seems like something which should happen to the more promiscuous Blanche. Blanche, understandably offended, fires back that "AIDS is not a 'bad person' disease, Rose! It is not God punishing people for their sins!"
- Invoked on Lucifer when a woman tries to get revenge on a guy who used her and dumped her by tricking him into falling in love with her (she meant so little to him that he didn't recognize her), faking her own kidnapping so he would pay the ransom, then killing him and running away with the money. Lucifer was appalled by the Disproportionate Retribution and said that a simple STD would have been a much more fitting punishment.
- Misfits had an episode with a woman who had the ability to give people superpowered STIs. Hilarity Ensues when promiscuous and (seemingly) uncaring Rudy fell victim to it and has to go on a search to find said woman and make it up to her before his member falls off.
- Played absolutely straight on My Name Is Earl: Earl wishes to make amends with his ex-girlfriend Natalie, with whom he had broken up by faking his death (in order to avoid hurting her feelings.) Her new boyfriend, Dirk, decides to emulate Earl and fake his own death, and hang out at the motel with a prostitute. Due to the lack of condom machines, he uses motel-issue shower caps instead. Eventually, Natalie discovers his deception and presents him with his Karmic Comeuppance, although Probability was almost certain to bring this one about, so Karma could've taken the day off.
Natalie: Hey Dirk. Still getting your mail. It's from the clinic: Somebody got themselves an STD.Dirk: I can deal with that.Natalie: Turn the page.Dirk: Aww crap... Damn shower caps.
- In the song "Schadenfreude" in Avenue Q lists "Exes getting STDs" as one of the many things you're happy to see happen to someone other than you.