nope, no problem but its got to be within reason and done the way i would do it, ie, not smacking, not yelling just getting down on his level and telling him no, he cant do xyz because of xyz IYKWIM. i tend to be a bit wary doing it myself tho with other people kids (except people who i know wouldnt mind) cos i know a few times i have asked a friends lil boy (who is a pusher) to stop and my friend got a bit funny about it. i would like people around me to pull DS up more, he gets away with murder with my MIL & FIL.