Sexual harassment

My girlfriend has this boss who is constantly sexually harassing her and its taking everything in me not to beat this guy senseless. She is afraid of losing her job if she lashes at him for it. And I'm not aloud to say anything either but it doesn't seem fair. The restaurant she works for has 2 lawsuits filed against them for the same reason. My girl doesn't wanna go that route. She just wants to be recognized for the great job she does at work. Anyone have any suggestions on handling this. I really don't think doing nothing is the answer. The owner of the restaurants know but does nothing so my chicks manager has no consequences for his actions.I really don't know what to do..and I feel for any girl that has had to go through this, its not fair and not right. No means HELL NO.