Is wrong or bad to fight about ?

Some times I get mad at my boyfriend when he doesn't wait for me to "climax" and instead just climax's himself. It happens every once in a while and I always find it so selfish of him. I do give him freebies every once in a while, so its not like I always have to have mine if that makes sense. Am I being equally as selfish for getting upset about it? He denied me once or twice, and got mad about that too. That's why my main question is......Is fighting about for any reason wrong or bad?