Well you really can't make someone like you but try to do stuff that she likes; make her laugh and just be her friend for a while then tell her how you really feel.
It means he just is not interested in you. He is more interested in the girl he went out with.
Remember, NO means NO.
If he said he likes you already...go for it.
Probably not the answer you want to hear but - leave them alone ! As you said, she's already in a relationship, and it's not your place to interfere.
Unfortunately if she said no, you might have to accept her decision. you should never have to change who you are for a girl. The right girl will love you just the way you are.
She already said she likes you.
you just tell her the truth and hope for the best maybe she will say yes and if she says no, there are plenty of other girls
you kiss her
Sometimes girls are shy, I know, I am one. But if the girl has said no, then you should stop thinking about her and don't try to persue a relationship.
Maybe she just doesnt want to go out with you.
You should wait for her to answer you if you have already asked her out.
Keep tring to get the girl someday she will like you. Like me okay:)