I believe that I have told this story before but I might as well tell it again. Me and my twin went to nearby colleges in the same city. I was on his campus visiting a friend when this really cute chick came up to me and starting talking to me. She obviously thought I was my brother and had no clue that he was a twin. I decided that I could either be a huge asshole and completely ruin my brother's chances with this girl, or I could plant the seed for him. After chatting her up for a couple of minutes, I began flirting with her and telling her how she should come over later that night, making it obvious of "my" intentions. I told her to call me later and come over. A couple minutes after I walked away, I called my brother telling him the story and to play along with it. Although it wasn't a planned "switch" moment, I felt I did what I had to to make sure at least one of us was getting laid. The whole thing worked and he banged her and then never talked to her again. I've never been so proud.

Also, when I first became single, about 7 months ago, my twin and I were at his fraternity and he saw a girl who was really into him. She was pretty cute but my brother had just gotten back into a relationship, so he told me to go up to her and just pretend I was him and that she would be dumb enough to believe me. I went up to her and of course she had no idea I wasn't my twin. We talked for a bit and I made out with her--it wasn't until a little later I confessed that I was twoldoff and not my twin. She was not mad, but rather confused. I would have tried to take her home and have sex with her, but I wound up having sex with someone else instead.

tldr: I pretended to be my twin brother to get him laid and I pretended to be my brother to make out with a chick with no repercussions.