I had a friend who basically was the female version of myself, same thought process, same likes/dislikes, same personality and even looked alike. We constantly got asked if we were twins. Then, after no, they would ask if we were dating and we said no again. I don't think dating (and therefore, having sex) with someone like you is a great idea. Her and I talked about this, shouldn't the other person complete you? 'Cause otherwise you would both get bored quickly...