AITA for being mad at my bf cause he won’t travel with me to take care of cats?

My BF (M30) and I (F26) bought a trip 3 months ago. It’s a 5 days trip that it’s gonna happen next wednesday. Also, it’s a trip we scheduled with my parents and his (they already know each other, we’ve been dating for a long time). We all bought it together in August.

What happens is that my in-laws have a lot of cats in their beach house (where they live). And there’s a specific cat that my bf’s sister rescued from the street a couple years ago while still a kitten, we’ll call her Pimpi. This kitty really attached to my bf and he to her. And it’s great, I love her and the other cats they have. He’s really caring about her, not that he doesn’t like the other cats, but clearly he only really cares for Pimpi in many occasions (like trips, dogs going around the house, other cats that enter etc).

So today, my bf texts me:

"Bad news. Will not make it to the trip."

I questioned, and he said "mom and dad didn’t ask for my sister to come and care for the cats, and there will be no one to care for Pimpi".

I then asked about the woman his parents usually pay to go there when they go on trips, to put food, fresh water and clean the sandbox. He replied that it’s too much time for them to be alone.

His following texts were:

"My parents are really irresponsible"
"But it’s not my fault"
"My parents didn’t even talk to my sister about it"
"And in the end, it was my sister who brought Pimpi inside, it’s her responsibility too"
"I’ll ask if she would go, but if she doesn’t compromise with it, I’ll have to stay, unfortunately"

And to make it clear, I get that animals being alone for a long time can be really stressful for them. Don’t know it the sitter going everyday really solves the problem. I don’t have pets so I don’t really know. And I really appreciate how caring he is for Pimpi.

But I told him that I thought he also carried responsibility for the situation, bc even though he cares so much for Pimpi, he didn’t even ask his parents about how they would make sure of their well being during those 5 days. He only cared to ask now (few days from the trip). He puts responsibility in his sister for having brought her inside, but he was the one that "adopted" her as his cat and she is the only cat he actually cares about. And what gets me the most is that he doesn’t see that he has responsibility to try solving the problem.

I was going to his folks today, but after this I decided not to, bc I’m mad at him and don’t wanna listen to them fighting about it and my bf putting the blame in everyone else but him, and putting himself as a victim. But now he’s mad at me for saying all that. He even said "When you have a baby, leave him for a week being fed by a sitter". And god, for me, it’s two completely different things. In the end, he said that his responsibility is to take care of Pimpi, and that’s what he’ll do. But for me, his responsibility started way before, and he doesn’t want to be held accountable.

AITA for thinking like this and being mad at him?