My girlfriend's sister is always quiet and I don't know what she's thinking. That's why I don't really like her. But she's beautiful, and on top of that, she's always braless at home and her nipples are always erect, which is strangely erotic and I look forward to going to her house. It seems that her sister had a fight with her sex friend and she seemed to be in a bad mood. I was thinking how nice it would be to have such a beautiful sex friend...but it seems she was looking at me as a potential new sex friend...