Why do guys give some girls mean looks?

I'm just curious....... is it a flirt or what? last night when me and my friend were shopping at a clothe store, for some reason this dude thought I was staring at him! So when him and his girlfriend walk passed us he was joking around with her until he caught me looking at him then his facial expression changed for a dirty look. He seemed very mean and weird... I've had a lot of guys do that to me... is it because I'm ugly???? :(

I doubt that you are ugly. Guys are just jerks. People don't like being looked at makes them feel all exposed and vanurable like their under a microscope or something. Don't take it personally just smile and move on with your day :)