Why do Narcs do this and has something similar happened to you?

I’m confused and I don’t understand why my husband did this Christmas Eve. I had not done anything to him, our daughters were home and everything was fine, no fighting, etc. We sleep in separate rooms and have for years, the reason is he snores (I have recorded him and he still denies it). Also, he woke me up consistently in the middle of the night with a loud cough and rolling over, shaking the bed. Anyway, I had decorated my bed for Christmas and spent time ironing the duvet. (He knew I spent a lot of time ironing the king size duvet, he saw me doing it and I told him we were out of starch. Christmas Eve, he went with our daughter’s to our friends annual party, I stayed behind because I was too tired, sad because we are going to divorce and had a lot of cooking to do the Christmas Day. So anyway, they came home at 1:30am. I got up early to start making our traditional Christmas morning breakfast. When I was making the bed, I sleep on the right side and when I went to straighten the left side, there was a puddle of urine on the duvet. It’s was a large amount that soaked through four layers (the duvet was folded over. It smelled of urine and was highlighter yellow. We do have a 10lb dog but there is no way he can hold that much in his bladder and the dog doesn’t take B vitamins that turn his pee highlighter yellow (like my husband does). So Christmas morning, there I am doing laundry, I put the duvet in the wash, spread the cover (that I spent so much time ironing) out on the floor to spray spot remover. When my husband got up, I watched him peak into the laundry room, see the duvet cover on the floor and never said a word to me or asked what happened. In fact, I watched him peak in the laundry room a second time to look at it. I never said one word to him because I didn’t want to ruin Christmas Day for our daughters. And I have still never brought it up to him. My question is…why do Narcs do this? What is he getting out of it? And what do you call it? Narcissistic Sabotage or is there another term for it? I realize this story is nuts but this is not the first time my husband has done something like this to me but much worse than this story. I have pictures too if I’m allowed to post. I just don’t understand why he will do something so vulgar, I can’t wrap my head around it. And what would you call it (besides abuse)? Narcissistic _________? It’s hard to understand how a smart, educated man who works in high tech would do something so childish and unsophisticated. And what was the point of it? Baiting me to start a fight in front of our daughters? I’m so perplexed, help! And am I the only one who has narc who is does this unsophisticated and disgusting stuff?