Yea the father can't touch the kid as far as i know, at least now anyways. If he was there then yes he wouldbe able to at least stop him, but now is premeditated assualt (im not all that good with these terms....yet ). As far as beating him up, it would seem heroic and allbut nothing every gets solved by teens fighting and its not like the movies where the girl will come running into your arms. She'll probably think your a creep.