I watched that whole scene as it was happening on E4, and although I did worry someone would get hurt, I didn't think Jonny was doing anything that bad.
As the others have said, Jonny and Kate are always rough housing with each other, and I don't think for a minute Kate has a problem with it. I believe if she did, she would say. I did see him wonder if he had gone too far and he made sure she was ok, and she was. It was great entertainment as they were all consenting and having fun. As I said, I was a bit concerned things would get out of hand and someone would get hurt, but that didn't happen.
