About a month ago my younger brother and his pal were hanging out in a club, sarging the ladies and stuff, and when my brother's pal went to the bathroom a guy went over to him and with no introduction threw a "what do you think you are doing" out of the blue(the guy never saw him before) and took a swing at him. What do you do in that situation, is it ok to return the favor?

Well... I'm assuming a line like "why sir, I'm washing my hands" wouldn't be very effective considering you'd already be getting hit. Probably try to swing back and hope for the best.

Duck lol or swing back. Most clubs out here, you're getting tossed either way. Might as well go out in a blaze of glory.

Those are some of the dangers of pick up my man. You are out talking to other girls and guys (especially insecure ones) will get super possessive of "their girl"..... even though she was the one all over you. If your brother creeped the girl out and told her boyfriend... That might also be the case too.

I've had that happen to me before. I am a boxer with nearly 10yrs experience so I try to avoid a violent encounter at all costs because I have a lot to lose. Usually there is room to talk the attacker down but if not defend yourself to the best of your capabilities. What I have done before guy swings at me I drop him with a liver shot. Its not as obvious that way and in my case security thought the guy was fall down drunk bounced him and I carried on a about my night. That being said if its at all possible walk away without violence! If its not what I tell ppl if you're in a self defense situation DO NOT worry about legal consequences at the time just make sure you're the one going home safely worry about the other later. Hopefully that helps you out a bit

Train martial arts. Definitely agree with going for body shots. Most guys will get floored by a liver shot because they expect you to be head-hunting. Body shots are harder to dodge and if you mess up a guy's face it will make you look like the agressor if security / bouncers get involved.