ExDP disagrees with me.
DS is 5, a bright and well behaved child.
He enjoys being hit/hurt. He will BEG people to hit him.
His best friend at school can be quite violent in general, but DS lets him punch him because he "likes it". He will ask for his friend to hit him harder, I've seen him hit DS really hard and he just laughs. I always intervene when I see it happening.
If he's playing a rough and tumble game it's always "hit me" "hit me in the face" "hit me harder!".
What the hell? Ex finds it funny and I find it worrying.