It's a pattern. now what?

our 3 year old was painting. bf came home and said he had to go to home depo. I wanted to quick hop outside, and asked him if he wanted me to mix new paint colors before I did. He said yes. so, I'm mixing the paint colors, (have to add water to them) and he raises his voice out of the blue and says I'm taking to long. I said " don't act like that in front of (our 3 year old)". He gets up, gets louder and says "if your not going to take my feelings into consideration which is what you shit on me for all the time, that's bs." I said "you shouldn't be acting like this in front if him" he said "okay so now I'm the bad guy" and tries to quick shut the door to leave" i quietly said "whatever " and he stopped and yelled "WHAT?!?" so I repeated myself. I'm very proud of myself for keeping calm when he's been very mentally abusive and tries to be intimidating. But now our three year old feels bad and doesn't want to paint anymore because bf made such a big deal about the paint colors. 💔 now what?