I have two kids, a son and a daughter, my son is 10 and my daughter is 9. Earlier today they were play fighting up in my son's room, I went up to see what was going on because they were making a lot of noise. So I peered through a gap in the door was left open and my daughter was sat on my son's face, it seemed like play fighting so I decided to just leave it and let them get on with it. But now I'm wondering whether I should have done something, should I talk with them? because my son didn't seem to resist.