Public Transportation

So me and the woman were heading home from downtown (thank you Boston Pizza). We're on the skytrain a few stops in, the woman asleep beside me. Some guy who looked and dressed exactly 50 Cent walks by from behind us, and sits on a seat like ten ahead of me. the train is half full at this point, and this guy starts staring me down. I'm not staring back, but every time I glance over he is still staring me down. This goes on for like five stops. Then he gets up shuffles over, and sits right behind me. I dont dare turn around, out of fear of provoking him. Then gets up and leaves at the next stop. When he is gone I turn around and half expect to see a bomb on the seat. Normally a guy like that wouldnt bother me, but wierdo's seem to flock to the skytrain, and that scared the crap out of me.