In the earlier time (Back when there were no humans to record this) I sign of biting often meant that the male or female was or is breaking up with the partner.
He's hungry
it means he was to f**k you dahhh
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.
When a man bites my neck, it's an instant turn on. I mean, right now, find a bed. It took me a few years to develop this, as a young woman, I didn't like it. The older I got, the more I enjoyed biting, and being bitten.
They like 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.
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.
He's just really horny at the time and wants to fool around with you.
How old are you? I mean seriously. And most likely because that is strange.
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.
Thor
She probably feels pressured or uncomfortable about sitting there because she isn't ready to have sex.