What does it mean when a guy looks back and forth between your eyes?

[norasq]

A crush did that then looked at my mouth(I was smiling) then looked back at my eyes and returned a big smile does he like me-what is he thinking?

[DishLady]

(1) He's slow about reading your body language, so you caught him glancing at your smile. He smiles back because he now knows that you are inclined to be friendly and accept his attention.

(2) He wants to kiss you. A staggered or lingering look directed at the eyes, then the lips, and back to the eyes is classic "I want to kiss you" body language. He smiles back and possibly blushes a little because he's caught up in imagining what it would be like to kiss you.

[coreenaa]

He's thinking about kissing yooou

...or you had something stuck in your teeth, haha

[yesman86]

Pretty classic want to kiss you but not sure face. I wouldn't take it as a bad thing unless you don't want him kissing you.

[MrFlirtatious1992]

He's thinking about kissing you. I do the same thing :)

[BoobMan]

Definitely sounds like a good thing. Most of your facial expression will come from your eyes, with most of what's left coming from your mouth. He was studying that and liked what he saw, hence the smile.

[ArrograntWarrior]

Just making sure whether both of your eye balls are of same size

[Guysensei]

can only be good..