I have always despised the "boys will be boys" excuse. When everyone else was saying, "He's just trying to get your attention because he has a crush on you," my dad was saying, "Who cares if he likes you? Do you want to be with a boy who hits girls?"
That's what I tell Pooka: Who wants to be with a boy who shows his feelings that way?
And that's what I'm teaching Boy: Do you like when people hit or yell at you? Then don't do it to them or they'll avoid being with you.