So I can calm down and not 'create a tense atmosphere' for the rest of the evening.
I don't want to write a big essay so I'll try a shorter version. DP needed me to do him a favour, a very difficult one involving heavy lifting, as he has an injury and can't do it himself. I did the favour no questions asked. He asked me, mid lift, if he could do anything to help. I said 'yes, please keep DC in the front room'. He said okay. Then he let DC run upstairs behind me. I was in the middle of lifting heavy thing, so I didn't want to also be anxious about DC getting hurt. I called out 'I asked you to please keep him in the front room!'. He told me to 'chill'.
Later when I asked why that happened, he got a bit arsey and then said it was 'no biggie'. I said to him that he didn't know why I'd asked him to keep DC in the front room, he said that not everything has to go according to the plan I have in my head. At that moment in time, I thought he was a huge dickhead. I replied 'whatever'. Since then, I've been trying to just carry on as normal but for some reason I just feel deeply annoyed.
So please help me to calm down, people of MN. There are more important things in life than focusing on petty insults.