This is just me but I'd stomp his a$$. If you can't do it directly, nothing shows the love like a bat to the back of the knees and you and a few friends practice tap dancing on his face. Sure it's somewhat cowardly to ambush someone, but if the circumstances are that you'll get fired for a straight forward brawl, then that is all you can do. Well, other than letting it go. I personaly don't put up with other peoples BS. Especially when it is of that nature. There is another option that I know of but it is a pain in the a$$ and lots of drama. You could talk to him in a public place and make it seem that he's more or less picking at you. Call the police and say that he threatened to attack you. They'll say they can't do anything but they will make a note of it if an officer is dispatched to talk to him or you. That is the foundation for the plan. Now that you have created a history with him being the bad guy, just say that he is hitting on your girl and you asked him to leave her alone and he got violent, you are ready for the big finish. Have a few friends that you know wont crack or screw up a story meet you somewhere that you know you'll have a shot at catching the guy alone. Set up a fake scene. Like act like you and your friends are working on your car's sound system and you just happen to see the guy. Make sure no one is around and straight up stomp his a$$. Then have a friend call the police and say that his friend (you) is being attacked by some guy. Not only will he get his a$$ kicked but he'll get arrested. Now you can opt to not press charges if you want, but wait because he'll most likely file a warrant on you. Now all you do is talk to the DA and explain that you were attacked and be sure to say exactly that you "feared for your life". Have your friends say that all they saw was you and the guy talking and then he just attacked you. You have witnesses to colaborate your story and basicly the guy will be screwed. In the end you'll both drop the charges and you will have gotten your get back. Trust me I've been through this many times. I have no respect for people who can't respect the boundry of a relationship.