AITA for being upset with my bf for canceling plans to hang with his friends

Hi everyone. I'm usually not this petty, but this has been a reoccurring issue. My partner [24M] and I [24F/NB] have been planning all week to spend the entirety of Saturday (today) together. He asked me Thursday if I could try to "get all my work done" on Friday to ensure the entire day was available for the two of us. I agreed, as we haven't had a day alone together since our vacation.

Today (Saturday) rolls around, and this morning he informs me that he has to run an errand at 12:30, will be home by 1:00. No issue, do what you need to do on your day off. But what made me upset was when he said he had forgotten about the plans he made with his friends, you know, the boys. The 3-4 of them had mentioned watching a movie together, but no plans were set in stone.

My partner decided to cancel our evening plans so he could go see the movie with his friends. I normally wouldn't be too upset if he asked to hang out with his friends when we already had plans, but the kicker is we are housesitting for his friend. I'm currently stuck at his friend's house babysitting four dogs alone now, the other options is to kennel them all night and go out. I don't find that fair, we committed to taking care of these people's animals, and I also don't find it fair that it's not my responsibility and I'm left alone on a Saturday night so my partner can be with his friends.

He left very angry, accusing me of being a narcissist because the situation isn't about me. He said I ruined his day because of my attitude after he canceled our date tonight. I don't know, AITA?