Should I go or not?

Hey guys, I have told you a few times that there is this guy that I was (and to some extent still am) mad about, like totally inlove, but he is straight, he rejected me, we remained friends and he left some time after to live abroad , then he came back but in another city and now he is back HERE. It was really hard to forget him. He has birthday on Monday and has invited me. Should I go or not? Advice would be appreciated!