They like you
He's just really horny at the time and wants to fool around with you.
He's hungry
Biting his lip could be a sign of nervousness, attraction, or anticipation. It can be a subconscious gesture indicating that he is feeling self-conscious or sexually interested in the girl he is talking to.
That he wants you to help with some framing? Hold the nails and pass them to your guy one at a time as he hammers them into whatever he's building.
He might be a vampire or he's just weird.
it means he was to f**k you dahhh
It means that he has no respect for woman whatsoever, and I am a guy answering this.
How old are you? I mean seriously. And most likely because that is strange.
A guy who is picking his nails in class may be nervous. That is only one explanation. Another explanation as to why a guy may be picking at his nails is that they have dirt under them and he's trying to get rid of it. Or it might be a habit of his to pick at his nails when he is bored.
it means he is either nervous or unsure, angry, bored or it may even just be a simple habit.
It means he realised he was too "forward" by smiling at you, so is now trying to control himself.
Well, guys if they want to get there nails painted they usaully get clear.