When your talking they will look at your lips or they will lick their lips or bite their lower lip.
They're hungry.
No it doesn't mean you have mental problems I bite my lips sometimes but i have no sign of mental problems ocasionally people bite there lips because they are usually nervous or scared. Mabye, though, if you bite them to make them bleed constantly.
yes
Everybody bites their lip.
Yes, absolutely, the majority of mature women have larger inner lips than outer lips. As a midwife I have seen more than most.
sometimes we bite our lips because we are nurvous about something or it becomes a bad habbit so if you see a boy biting there lip and there staring at you that could mean he likes you
Probably the same way you do for women, lips are lips
You are probably biting your cheeks and lips from stress, like some people bite their nails. Try chewing sugar free gum or eating hard candy instead.
No, they have upper and a lower lips only.
yes guys do like lips (from women not from men)
by erotically grabbing their hips and bringing them close to you perky lips, then in a swooping motion ferociously lock lips with his neck