When I went to my girlfriend's house to play, I encountered her super cute sister. I couldn't help but be more interested in her than her. I decided to attack her, and although she didn't seem to like it, her resistance was weak. I took the plunge and rubbed her breasts, fingered her, and gave her a forced blowjob. I went ahead and fucked her. Since that day, her sister has been addicted to my dick, and we've been secretly fucking every day without her finding out.