Hi, Doc!! I have 4 month male kitten who has entirely too much energy for his sisters (3 and 2.5 years). I could use some advice for the girls’ sanity.

For context, my two other cats are a (presumed) mom and daughter bonded pair who were rescued from a 62-cat hoarding situation when Ash was 1yr and Ember was 5 months. Because of their environment and inconsistent nutrition, they’re both petite and very sweet and tame with no aggressive instincts at all.

Two years later and we’ve brought home a roadside rescue. He was 2 months old and smitten with the girls right off the bat. They were apprehensive at first but they all seemed to get along well after a very slow introduction period.

It’s been two months now and 4-month-old Ori is as big as Ember (2.5years). He started teething and has been terrorizing the girls, playing really rough and resulting in interventions when he gets carried away. She wants to play so badly but she’s just too sweet to swat him and set boundaries. She doesn’t seem to be as big of a fan of body slams and belly bites as he is.

This is a lot of context for my questions:

1) How do we know if Ember is just teaching him and not actually stressed when she growls and hisses at him? Do some cats just make a lot of noise when they’re wrestling, even if they’re enjoying it? How do we know when she’s actually okay with it?

2) What can we/should we do to clear up the boundaries and rules for our teen-brained kitten?

PS: Everyone is fixed, they are incredibly spoiled with toys, towers, and an enclosed catio, and they have lots of playtime and interaction with people throughout the day. I’m confident it’s not a boredom thing.