My slutty sister

<p>I went to a group party without telling my girlfriend first. Here I met a beautiful sister who didn't seem to care about me at all. A few days later, when I went to my girlfriend's house, I was surprised to learn that the beautiful sister at the party the other day was her sister! And unlike that day, today she deliberately approached me, seducing me with her seductive lips. Unable to resist her beauty, we continued to secretly fuck each other whenever our girlfriends were absent. Some time later, I confessed my love to her, but she flatly refused. You only care about other people's boyfriends. If I still belong to someone, our relationship can still be maintained...</p>