How do you keep calm and let things roll off your back when your spouse says things on purpose to stir you up?

He says these little things to get me going I think on purpose to get a rise out of me, then when I do get a rise he says I'M the one arguing, not him and he doesn't know why I'm acting crazy. For example: There was an issue at my sons daycare with them putting him on the tile floor instead of the carpet (he's 4months), I handled the situation calmly, spoke to the director, asked if they could do it differently and that was the end of it. I didn't want to cause trouble for the people who care for my son when I'm not there, so no I didn't yell or get irate. Besides that I'm an adult! He wanted me to go in there a raise hell! When I explained why I didn't cause a big scene he says something like "Well I guess if you care more about hurting feelings then taking care of your son then that is your problem. Why don't you care about your son?" This, to me, is RI-diculous!! He got me all wound up by saying this! He KNOWS my son is my everything which is why I handled it the way I did. Why does he do this? When someone says something to make the hairs stand up on your neck how do you just relax and let it roll off your back without getting upset? He says things like this ALL the time, not about my son but just anything! Making preposterous accusations!