Roommate not on lease refusing to pay
My roommate and I lived together for a year before she decided to move her boyfriend in. We came to an agreement that it would not be necessary to put him on the lease, but that he would pay 1/3 of the bills. Two weeks ago, he threatened me, got confrontational, and told me to move out, to which I replied, "Gladly". Now obviously he doesn't have the right to kick me out of my own apartment, but I felt that I didn't deserve to have his anger directed at me, so we broke the lease and everyone moved out.
The fees involved to break the lease are a month and a half's rent. $1620. When I told my (ex)roommate that I would have my third ($540) paid as soon as possible, she said I owed HALF, that he wouldn't be paying any of it because only our names were on the lease.
Is this worth taking to a small claims court? Do I even have a case? I read somewhere online that an oral contract is just as sound as a written agreement. All I need to do is prove that he was, in fact, a resident. (which I can do with bank statements, signed letters from neighbors, etc)
Suggestions?