How can i punch and break someones nose without breaking my hand?

so my sister has been going out with MY boyfriend for over a few months now...i just found out now and the only way im going to feel better is by giving her a nice punch that will break her nose and remember me for a little while..I want to punch her nose and break it but i dont have much experience so how do i do that without breaking my hand?|||No it will not help|||Don't close your fist all the way, leave your middle knuckles in your fist sticking out so there is no pressure being applied to the bones in your hand, and cock your fist back for an Ali haymaker , aim for her nose real fast, then with all your force, hit her right in the center of you nose.|||You will regret it later when you actually grow up. But for arguments sake, dont punch, either head butt her or knee her in the face, hard to break your head on a tiny bit of cartlidge.|||This is hillarious to me|||strike with your hard palm in an upward angle to the nose. but rather do it to your bf instead of your sister|||I'd say they're not even worth it. Move out of your trailer park and forget about them.