As your friend, I have to wonder why you're worried so much about an empty threat. Are you planning on doing something that would cause me to have to punish my house? Otherwise it's an empty threat, mate.

As your Quidditch opponent, you know good and well that you can't go easy on your friends. I might even go as far as to say especially your friends.

S'Pointless though, I'd probably get fired if I gave ya so much as a bruise.