Well, There Are About a dozen possible reasons, but I'll give you three.
1. Very Tough Girls, all Have their sensitive side, so when they crush on guys, it tends to show up on their hard side, not all the time, though.
2. Some just plain bratty girls, will give everyone dirty stares, you get used to it.
3. Most Girls, Unlike Guys, Get the whole relationship and crushes, worked up in their mind. They "exaggerate. So when a guy they normally talk to hits on another chick, they get emotionally unstable.
Mny reaons they will give a dirty look is because they don't like each other or they are having jealous prooblems
The girls are just jealous of you and the guys probably like you.
coz it can lead to soemthing "dirty" Guys have trust in women. For instance, girls are not sloppy and guys are.
They are lusty and they fulfil their fantasies.
It depends on the guy, but generally girls who look "better" tend to get more attention from guys.
unfortunately, some girls judge guys on their looks. But the good thing is that most girls can see past looks +, everyone likes different looks, like I like guys with brown hair and my friend likes red hair, my friend only likes guys with six packs whereas I dont really care. The thing is that if girls cant see past looks, they dont deserve you :)
Guys Notice girls by looks first, but in the long run the personality matters incredibly
you get girls to think your attractive make yourself look like a take a shower a everyday. but also give them that dirty look. also the most important rule BE YOURSELF GIRLS HATE FAKE GUYS.
Sometimes girls get nervous around guys, they give them "butterflies", but I wouldn't say girls are intimidated by them.
Guys like dirty things. I guess they just like looking at the girls bodies. :) Weird, but the truth. :P
Depending on looks and how good it is.