People keep saying "he shouldn't have fucked his sister" but he is at best 15 and she is at best 18. He's in JP middle school so his age ranges from 12-15 and hers from 18 to fucking post-grad, or maybe more "realistically" 18-22. It's entirely possible that he had as much say in the incest as any 13-year-old had in something their 20-year-old sister decided he was gonna do. He just had too much middle schooler swag to live a normal life with a normal girlfriend.