SSNI-871 _Craving to fuck my sister-in-law

My girlfriend and I have been together for three months. Today was the first time I went to her house. I heard that her sister was also at home so I thought I had to greet her well to make a good impression. When she came down from upstairs, I almost froze when I saw her J-cup breasts without a bra!!! She was only wearing a thin shirt and I could almost see her nipples, it couldn't hide her charm at all!!! I couldn't resist such big breasts, so I unconsciously approached and touched her. But she didn't get angry at me, she accepted me, she allowed me to squeeze her big breasts, soothe my hard cock, and even allowed me to make love to her!!! I completely lost my sanity and frantically made love to her even though my girlfriend was by her side...