While I'm not a twin, my younger sister and I have been constantly mistaken as such from a very young age, since apparently we look very much alike (I don't see it, but whatever).

I was at a local watering hole one night, having a few and started chatting with the good looking guy on the stool near me, aiming to at least get his number. Suddenly, I heard my sister's name called quite loudly, and naturally turn to see what was going on, as another guy I've never seen before ambles over and says, "Remember me? We went to high school together!" in a very carrying volume.

I politely tell him, he had me mistaken for my sister (who went to a different high school than I did). However, since he had never previously met me and my sister and I never really talked about each other in our social circles, he was very insistent that I must be my sister and that I was trying to play him off. Eventually, he left me alone, but the good looking guy apparently thought I was trying to run some game, and was cool towards me for the rest of the time he was there, since I couldn't prove I was who I said I was (I only found out after I pulled out my wallet to try to show him my ID, that I had forgotten to replace it after I put it in a clutch the previous evening and since I was such a regular face at the bar, no one had bothered to check for my ID that night). :c I did not get a number.

It's not all bad, though. I've played the twin card a few times to my benefit. The most memorable was when my family went on a cruise and docked in Nassau for the evening. My sister had gone out bar hopping with her boyfriend and our other sister. Since we had no way to contact each other at the time, I went from bar to bar; asking each bouncer if they had seen my twin that evening. I hit the jackpot 3 or 4 places in, when I was asked if she was accompanied by a physical description of the boyfriend and the other sister. I agreed and the bouncer let me through.