Incest

"But that's mental! Why would any guy want to fuck his own mum?" "Yeah. You hear about it on the news and stuff, though. Mums who fuck their sons, dads who fuck their daughters and their sons. Brothers and sisters who fuck each other—" "Language, please!" Miss Azley protests. "That's bullshit. Who would want to fuck—sorry, screw—their own parents?" "It's called incest, man." "That's when a guy rapes his sister, dickhead."

—Miss Azley's English class,  Forbidden

People that have sex with their own relatives.

Examples

 * Kenny Afton(FNAF)
 * Asriel Dreemurr(Undertale)
 * Jason(Friday the 13th)
 * Alvin Marsh(IT)
 * Shannon Boxman(KO Heroes)
 * Ocelot(MGS)
 * Vince Mcmahon(WWE)
 * King Cold(DBZ)
 * Circus Baby(FNAF)
 * Him(Powerpuff Girls)
 * Blossom(Powerpuff Girls)