I’m looking for a sorority incest story I read at some point on literotica. The basic premise is that a brother finds out about some girls getting revenge on his sister so he goes over to stop them. Except that’s part of the revenge plot, and they get him to have sex with some girl that ends up being his sister. The girls then try to blackmail his sister with proof of their incest, but the sister just snatches the phone with the evidence out of their hands and they run off.