are you completely ignorant. are you looking for an ego boost? questions on here drive me crazy. guys and girls really aren't all that different, people act sometimes like were a different species, we think very similarly.
he's either checking you out,
he may think he recognizes you,
or maybe something caught his attention, maybe he was reading your shirt
Well I don't know. Maybe he was looking if you have leg hairs, or if you have poop stains. Or maybe he's interested in your fashin style, such as spotting the brand of your high heels or jeans? I don't know, what else could there be?
guys look to a girls behind when they look back. if the guy and a girl pass each other on the side and he looks to your back, well, he is definitely looking at you tush i. and it means he is totally checking you out.