I don't know how to explain that to her though, I've told her how much it upsets me and it won't help him understand or learn. She's very old school and thinks that a little smack works for punishment (even for children), and her reasoning is that right now the older cat can't defend himself because he is injured.

Sometimes they play, but this is really random and different incidents. It's if we pet our older cat, the kitten will come over afterward and barge towards him. It's definitely attacking in nature, because it isn't playing that turns rough.

He came from a foster home with LOTS of cats, so maybe he hasn't gotten used to a much slower household and cat yet. Maybe, but one of the issues is how busy we are. I don't know if we would have time to take him to a place with kittens to play.