Most Helpful Girl
The reason you're so upset over this new guy, is because of your hurt and distrust from the ex. And I've done this before, putting past feelings of another guy onto a new guy. I did understand that my reason for my behavior is so that I won't get hurt again, and so I looked for the red flags that I found in past guys.
I agree with ParisFarmer, that you should take it slow with this new guy. I think you need to find out more about this guy, and whether or not he still has ex girlfriends in his life. Just do your research on him first, before you start having sex with him. It's best to find out his history, because he might repeat the same relationship patterns he has in the past. I have avoided some bad guys by just asking " Why did your previous relationships not work out?" If he blames all the ex-girlfriends, then run... If he is still friends with his ex-girlfriends, then run... Don't trust that he's still friends with them because he cares, because having access to the exes only creates opportunity for him to cheat.
I think you should read relationship books, like the ones from Dr. Phil or other self-help books. I've learned so much from reading about these guys and their behaviors. Trust your gut, and have no regrets for protecting yourself against baiters...