I think I'm going to kick my cheating roommate out of my house.
Can you tell me more about why you want to kick your roommate out?
That asshole cheated and then he denied it.
You aren't able to kick out a roommate because they cheated on someone. That's their business and has nothing to do with you. If you don't like this person then you should get a new roommate in the future, but you can't tell them to leave.
I should be able to tell him to get out since I pay the extra 300 for the rent and utilities.
It doesn't matter if you pay extra, as long as he's paying his share then you can't kick him out for his personal choices. I think you should jus ignore it, and then look for a new roommate when the lease is up.