Why??

Most of the time when me and my boyfriend argue he gets me so mad that I feel like telling him I wanna breakup. But I really don't want to its just at the heat of the moment that I feel like saying it. I've never really broken up with him but I've told him a few times that I would just to see his reaction and scare him etc so he can change his ways because it's horrible how he acts like a child sometimes and is rude. I honestly love him so much and never want to breakup but why does my brain always think about breaking up when I never actually want to breakup with him??