I'm thinking maybe he has feelings for you to or he thinks you are cute. It's okay to think another girl is cute when you have a girlfriend; it's natural.
They are PROBABLY into you. So if you catch him staring at YOU wink and stroke your teeth across your bottom lip and make a smile!
that means that they are checking you out to see if you are there girl
He probably thinks your pretty, he likes you, or you have food on your mouth.
that means he likes or because your staring at him.
If you catch him in the corner of your eye look at him and smile BUT NO TEETH!
He either still likes you alot or he hates you with a burning passion
IT MEANS HE STILL HAS FEELINGS FOR YOU BUT WONT ADMIT IT
It means he thought about looking at you before, you thought about looking at him
he probably likes you and gets nervous when you discover he's staring at you OR he was surprised to see you staring at HIM.
1. she thinks you are cute. or 2. she thinks she knows you or 3. you are a freak
i think someone has a crush
It probably means, A guy likes you :). If you catch him looking at you and then quickly looking away, then that's one sign :D