Most Helpful Girl
I have sisters who are identical twins, and one is single and one is not. The single one isn't offended because the guy asked the other one out-- it's not like they're joined at the hip or something. They have different personalities and thus attract different men. You should just ask her out (when you two are alone obviously)
Most Helpful Guy
I have dated a twin and I am still friends with her. The biggest pitfall I see is that identical twins often have a stronger connection than other siblings because of their similarities, even though their personalities can be different. So, it is very important that the person’s twin also approves of you.
When I dated Sarah (not her real name), her twin took an almost instant dislike to me. She found things to criticize and campaigned to break us up. Ultimately we did break up, not just because of her twin but it didn’t help.
So, try to solicit the friendship of the twin while not crossing any lines. If they decide not to like you, you could be headed for a bumpy ride.