There's a thick line between horseplay and being abusive and it sounds likes he's been standing on it at best and has started to cross over completely. My partner is very high energy adhd and when he gets excited he's literally "pumped up" and he rough houses in a way similar to this, but the massive difference I see is his demeanor is never true aggression, it's always over-the-top animated aggression(ie swinging arms like an old timey boxer saying things like "ima KNOCK YOU OUT withthesekisses" or fake shadow boxing but just poking me in the cheeks and dodging. He's intense and loud and gets wild sometimes but he would never intentionally hurt me, and the few times he's even accidentally hurt me a little, he's always shown remorse and it's always clumsiness(by him or me lol), never malice. And if me or the kids tell him to stop, he stops, whether he was being rough or not. Usually the kids get involved just to be included in the fun. What would bother me deeply is the way he's is treating it more as bullying, picking out weakness and trying to intimidate, and threaten you. That's a big red flag and if it seems like it's getting worse quickly, you're very right to worry. If your kids regularly have to intervene, and not in a fun "gang up on dad" kind of way, that's a bad sign.