ANSWER:
She likes you! I do it all the time, girls find it hard to look the guy they like in the eyes because there scared. whether they were scared of you finding out or because they don't think they can keep a sraight face while looking at you. IT'S A GOOD SIGN!
she likes you back
People have different habits when the are on a one to one with another person and talking. Some people look at peoples eyes, while others look at the mouth. It really doesn't mean anything.
Yes, he is interested.
Amelia Mason says: If you are the girl he is talking to, it doesn't necessarilly mean he is flirting, it just means that he is not rude enough to look elsewhere. If you are not the girl he is talking to, it still doesn't mean for sure that he is flirting.
its Means he likes you ! If you look deep into a boys eyes and they smile they like you.
It may mean that he likes you and is shy to make eye-contacts with you. He starts talking to other girls just to hide his shyness.Or maybe he simply doesn't likes you.
Maybe he's saying she's looking at him but he's not talking about the way she's looking at him.
She doesn't like you and is ignoring you. She could possibly be lying to you.AnswerI would never trust someone who can't look me in the eyes, or at least make some eye contact, while talking to me. If a person is extremely shy they may do this. Otherwise, I feel that someone who cannot look me in the eyes while talking has something to hide, they are not being honest, etc.
it means he has been betrayed and is sad
Well if I understand your question correctly then when you're talking to her look into her eyes. That's a big deal. If you mean how do you catch a girls eye when you make eye contact wink at her and smile.
It really depends on the girl. It is possible she's being very shy, but it's also possible it means she's avoiding talking about whatever subject you are discussing, perhaps because it's making her uncomfortable.
you should probably turn around to see if he is really looking at you