DS is 4.3, and has recently started playfighting quite a lot. He doesn't really do it with other children, but there's a lot of running around punching the air and kicking and pretending the beanbag in the living room is a "baddie" and hitting it, etc.
So, as a first time mum of one with NO experience of boys (my family is all girls), is this just a harmless "boys will be boys" thing, or should I be discouraging him from this kind of role play?