Cartman, as he usually does, starts shit by writing terrible fanfiction of various couples and spreading it anonymously around the school. What he doesn't realize is the noncon fic he wrote about Tweek and Craig sparks a conversation about kinks and spurs them to try it out...in an abandoned classroom Eric happens to be passing by. He proceeds to have the most confused boner of his life.
Tweek/Craig, Cartman as a voyeur, consensual noncon/roleplay