NTA yet. You’re not an asshole if you think that way, but you could be depending on how you act

If you suggested a kid free meetup and they said they would bring the kids anyway then the conversation is over - if you tell them you don’t want anything to do with their kids then they will think YTA and you won’t catchup, which is worse than now where you just won’t catchup

Maybe just tell them you’re going somewhere kids can’t come like a bar, and politely decline any offers to meetup elsewhere

If you could do it better, they’d leave it up to you!

Beware the Idle Kantian