The Simpsons is one of the most popular cartoon shows in the Real World. The show, created by Matt Groening, started out in 1987 as a five-minute cartoon series on The Tracey Ullman Show and has been running as a half-hour series in its own right since December, 1989.
The show focuses on the lives of the Simpson family, a stereotypical American middle-class family complete with husband Homer, housewife Marge, and two-point-four children Bart, Lisa, and baby Maggie. They inhabit the town of Springfield, somewhere in America (exactly where is never specified), in an AU of the Real World in which people have bright yellow skin.
As with all fandoms that feature siblings, The Simpsons suffers a lot of incestfic.
Sometimes, people have the characters Marge, Lisa, or Ned Flanders doing immoral and/or bizarre things, possibly because they are canonically moral and sensible so they think it's funny.
So far, two missions have taken place in the Simpsons universe. In one, Laburnum and Foxglove slew an angsty Lisa Sue who, for inexplicable reasons, attempted to seduce her brother while they were both still respectively eight and ten years old. In the other, Steven Fontwell and Wallis slew a replacement in a bleepfic.