Is there something wrong with my ex?

After we broke up, he has constantly called and ask to see the new guy. Im with a new guy that lives not so far, maybe 3 miles away, and my ex wants to meet him. The thing is, im not even sure but the new guy had gotten into contact with my ex and AIM him, dissing him and arguing with him because i had told him about the situation of the break up and now my ex had "thought" in the end that he was a biual. Now my ex is all smug and acting tough and mighty saying he will "kick this guy's a**" he hasn't stopped calling me to check on what has happened or what im doing with him. Is there something wrong with him or is he just looking for a fight?