I have a beautiful girlfriend who I love and care for. But I also have a good looking sister who, i adore and lusted since I was 17 yrs old (Now I’m 26 yrs old). I love making love with my girlfriend, but sometimes I fantasize that I’m f****** my sister, when me and my girlfriend are making love. It is such a turn on when this happens. I would love to f*** my sister, but I don’t want to mess up my relationship with my girlfriend.