A few years ago I had a kid (about 12) squeeze through between my wife and I to get to his buddies, I said "HEY!" and he just said "Whatever". He planted his pole on my board and tried to push a couple of times, then tried to move his skis which put the edge down the side of the nose of my board.... I leaned forward and said to him very calmly "Here, let me help you". I then picked him up and threw him in a snow bank about 6 feet away, out of the line.
I didn't think it through, but people gave me more room the rest of the day.