DP is STILL upset about the time he had Ben and Jerrys cookie dough ice cream in the freezer and when he came to eat it, I had excavated all the bits of cookie dough out and eaten them. This was over a year ago. I may have been slightly unreasonable. He is now very protective over his ice cream. 
So share, in what ways have you been unreasonable in a petty way that is still held against you?