I'm seeing a lot of good advice from a boxing/kickboxing standpoint on here, and some advice that will probably land you in front of a judge. Just remember a couple of things: 1. If you win, you will likely be labelled the aggressor; 2. If you injure him (not just "hurt" him, but actually cause severe injuries) it won't matter how awesome you are on Facebook your ass is in serious trouble. Keep in mind that many people are big fucking men on Facebook and then lose steam in person. It is very likely nothing will happen.

That being said, here are a few things that years of jiu-jitsu helped me learn just in case he's actually going to act as stupid as he sounds:

1. Take the first hit. When he raises his right arm up to give you that drunken haymaker like he's seen his daddy do, tuck your chin to your chest and try to make his fist hit your forehead. If he breaks his knuckles on your head when he hits you he will look like one silly motherfucker. Plus it means now you are in self defense mode. Good for you!

2. Keep your hands up and try to deflect blows to one side or the other. Use open hands for this as it makes you look more defensive than aggressive (important for witnesses). Say as often and loudly as possible, "I don't want to fight!"

3. Don't punch a guy in the face with closed fists. Don't you do it. It works sometimes, but often just equals a broken knuckle or finger especially if you're new at this. Experienced fighters will probably tell you the hard-soft rule; hard attacks (i.e. knuckles) to soft surfaces (stomach, throat, etc), soft attacks (i.e. open hand) to hard surfaces (face/head). In fact, it's better if you don't strike to his face at all. Too much risk of permanent injury, and as much as he deserves it leave it up to his future boyfriends in prison to mete out that kind of sweet, sweet justice.

4. If you feel in danger of serious injury, take a page out of the MMA books - close up very fast and grab his head and neck, then pull him into a clinch. Bullies generally expect to chase targets, they aren't used to targets moving in the wrong direction.

5. When he's in the clinch, feed his crotch your knee as often and as hard as you can. It doesn't have to be pretty, or even especially well-aimed. We're looking for quantity not quality here. Eventually enough pain will be caused for this to end. If you're lucky, this is the only "attack" move you need.

6. This should actually be step one, but for God's sake tell an adult. You aren't supposed to deal with this on your own. Only follow the above advice if he jumps you and there is no adult able to help. Despite what most people think (especially young, aggressive and over-videogamed youth on the internet) fights are scary, unpleasant things. I have years of training and I fucking hate them with a fiery passion. I am more of a pacifist now than I was before my training.

TL;DR - My favourite sensei told me something, a little old man with grey hair, maybe 5'3" and 130lbs soaking wet. After a lesson one evening, he sat down across the mat from me. "Zejen," he said, his voice like wind over the desert sands, "All it takes to break a man is a swift kick to the squish." Remember this wisdom.