I don't understand what this means even in English. Is it "Man!" the exclamation, like "Man I'm hot!" or is it just listing "man" and 'boys" but for some reason with an exclamation mark?
It's more like 'Oh, come on now, boys! What the heck are you doing back there?', from my understanding. But that would rather be 'Man' with a single m, I guess. Maybe duo's intention is your latter remark, an imperative call for attention to a single man and several boys.