It could mean a few things 1. He likes you 2. He wants to be your friend or get to know you 3. A combination of 1+2
1. He is very nice and smiles at everyone.
2. He is nice but too shy to talk to you or ask you out.
3. He has a disability and can't help smiling.
the guy you have a crush on is checking you out
It means you were looking for your boyfriend!
It means he loves you.
They are talking about you.
No it does not
look for the mean character about your crush. Sure when his your crush you think his/her is all sweet and stuff but nobody's perfect so start looking for the mean things the guy/girl would do and hate him for that.
That means that he loves you.
he really missed you!
He's got a mad crush on you. I've had a mad crush like this for someone for almost four years
well it could mean alot compared on how he is looking at you.=If he is looking at you in a flirty way he is going to talk with you but if he is looking at you in a regular way he could like you or he could just be thinking about you=
It sounds like they have a crush or they were just looking at you. If they do it a lot, they probably like you. Try talking to them a little more, and be a judge as to whether they are into you.
It could be that he has a crush on you, or he could be just showing concern as a friend if you are looking a bit down.