We got into a fight sort of threw things_pillows my cell phone but he told his mom everything.now every time we argue he goes to his moms house and tell her everything we talked about? Wth is that wrong or what?

Well I think its okay to go for a little bit to cool off ; its okay he tells her things but it's a different story if he allows her to interfere with the relationship because he needs to talk to you about the argument so you can work it out.