This goes without saying..but that can get pretty dangerous I hope they had a safe word/wi...

I think thats what he meant by hand gestures. If it's closed in a fist its not ok, if its open then its ok. But thats quite risky too.

I thought it would mean slapping with an open hand is ok but not with a fist

Yeah thats what i thought at first too but idk, i feel like that could be the "safe gesture" in the context

I was kinda confused about that part but that explanation makes sense, thanks :)

actually the gestures are what's okay to do to his neck i believe. open fist, or not open strangulation. at least that's what i thought....hmmm, i wonder