When I went to visit my girlfriend's family, I met an incredibly attractive woman there, and for some reason she was very interested in me! When my girlfriend isn't looking, this sexually frustrated older sister seduces me with her erotic charms. "I'll teach you what feels really good." I easily give in to her temptations as she uses every trick in the book, and even though I feel bad for her, I end up having sex with her even though my girlfriend is right next to me!