The most likely reason is because she likes you.
It could mean a variety of things, such as admiration, curiosity, or simply being lost in thought. It's possible she finds you interesting or is deliberating on something unrelated to you. If it makes you uncomfortable, you can politely ask her about it or try to ignore the behavior.
They are talking about you
If a girl keeps staring at your belly button, it must mean you're not wearing a shirt or it's unbuttoned. It could also mean she likes you.
It means she likes you or shes just a creeper
she likes you or you are doing something that annoys her very much
She could be interested in you, or maybe she might think your kind of weird.
Something is on his mind.
She probably feels bad after what she did to you. Even if you now hate her after what she did to you she feels the same way as he was her boyfriend too
It means madly in love with you and can't keep hers eyes on you.
Probably but make sure she's not looking at your cute friend or seat buddy.
That he's checking you out!
Because he likes you and is jelious of your boyfriend
It means the same thing as usual; he probably doesn't like you.
it means you need to learn how to spell