Love all the support, guys!
Currently, when Harry hits I say “No hitting. We don’t hit." or “Ouch, that hurts mommy." Aaaaand, he laughs. I don’t think he “gets" what hurting someone else means. Or he’s a lil sociopath. Jury’s out.
I saw some advice on another site that I liked:
I’d just walk away without saying a word. DS went through a stage (at about 20 months) of hitting me and that’s what I did, no reaction but silent treatment for a couple of mins then went back said “mummy doesn’t like being hit can we play nice now?"