Me trying to be a nice guy to some random black guy at the rec center

So I went to the rec center today with my cousin to play some racquetball. We were doing our thing and having some fun and doing the usual stuff that we do. All of a sudden this random black guy walks into our court and ask us if he could join us because all the other courts are full. So me being this nice guy and all says yes. He explains a type of game we could play in racquetball with three people so me and my cousin listen and we start playing. All of a sudden my cousin who is not that good at this game because this is his second time playing gets yelled at and threatened by this black guy. This son of a bitch says "If you don't hit this next ball I'm gonna hit you." so im thinking wth is wrong with this fool. He thinks he can come in our court and say this shit to us. This fat piece of shit thinks he tough... i keep regretting not getting in this bitches face and giving him a good old beat down. So after the game we played he challenges me to a 1v1 thinking he can beat me and he all that. I beat this sucker 5-0. So after the game this sucker wants a rematch because he think he didnt do his best. Im like hell no bitch you come in here disrespecting my cuz and me.. go fall in a well you fat fuck. I was so ready to just knock this guy out if i wasnt so afraid what would happen to me in the end, but now that i think about it i really dont give a fuck anymore. If i see this guy again i think im gonna have to teach that fool a good lesson in respect.