There is really only one person that can definitively answer that and that would be the guy in question. It could be for a number of different reasons. Without knowing any specifics of the situation, I would guess that his friends could have something to do with it, but again it could be just about anything and without any specifics there's no real way to tell.
hold on to her shoulders really tight
There could be many reasons... He may think that the girl doens't like him back and believes that there is no point in chasing a girl that doesn't like him; he may not actually like her; he may be playing "hard to get"; he may have natural feelings for her but really not want to for various reasons so tries to ignore his feelings; he might like someone else as well or have a girlfriend; the girl could have a boyfriend; he could be ver busy with other things.
she really doesnt want to have anything to deal with you, or she will ignore you or diss you in front of your friends of course what would i know since im a GIRL
well all guys flirt. But if he is flirting maybe he still has feelings for this girl. maybe you should tell him it bothers you and i would definitely not ignore it.
you need to tell her your feelings
yes they can.
If you can not tell you already have feelings for this girl without kissing her, then you are being disrespectful of yourself and her feelings.
You could ignore your feelings for the girl you like, but this will probably damage your relationship with your girlfriend at some point in time. You are better off breaking up with your girlfriend, and after waiting awhile, flirting with the other girl. Your girlfriend will be extremely hurt, so think about what you do before you take any drastic action. If you really love your girlfriend, you will ignore these feelings of attraction to another girl, and tell that other girl that you are not available and to stop bothering you. Try to say this in a nice way, or if you really want her to stop liking you, (which I doubt but just in case) you could always say it in a mean way. But please, for the sake of us girls ;) don't.
he does not like her hates her or likes her
Ignore them if u really like the girl then u wont care about what ppl say.
This girl may dislike a guy for admitting feelings or mayby she might have for the guy.
You will know if he is true to his feelings for you. For me, as a girl, I would know that a guy really likes a girl because you can see it in his actions, not only in his words. Example is, he would do everything and may give up everything for you (like when his parents doesnt like you but then he really defends you from them).