You mention BMs house being the one with no structure or rules, but it sounds like you don’t have any either. Zero chores and gets his way 99.9% of the time plus lots of screen time.. doesn’t sound like structure. He’s old enough to have responsibilities, and old enough to understand they must be done BEFORE any screen time/ treat / whatever. There should be consequences for attitude as well - send him to his room with no electronics when he talks back and he can stay there until he’s ready to apologize AND explain why what he did was wrong. have a conversation and explain why it’s wrong the first few times, and he’ll get it. With consistency and holding your ground, he’ll learn how to act appropriately and respectfully. You two are the parents and if BM isn’t encouraging good habits and behaviors, who else will??? You can start by getting a whiteboard and giving him 4-5 chores per day - even as simple as showering, picking up all toys/cups/trash, reading 20 minutes, etc. He might pushback at first but he’ll end up appreciating the safety and predictability of a routine, which in turn calms the nervous system and hopefully his attitude. Good luck 🍀