I have 2 male chinchillas is it normal for one to be peeing and mounting the other?

So I've had a chinchilla named Kayak for almost a year now. I was feeling bad because I have school and I'm going to be working a lot that he might get lonely. I purchased another male chinchilla today and named him Paddles. When I put him in the cage Kayak Proceeded to mount Paddles and bite him. then he peed on him. Should I take Paddles back? or will they get used to each other and be friends?