What does it mean when guys ask this?

it IS a lame pickup line and one with no weight behind it. I came to really detest that question during my single days. if they are really curious they would ask you out.

they are trying to figure out what the problem is? If your good looking and single there must be a problem, too high maintenance, too uppity, bad personality, gay, gold digger all sorts of things can be wrong, just trying to catch a clue.

Guys think that, you are a good looking girl and they wonder why dont you have a bf.

its not a pick up line.

Even girls ask guys tht, how many gf's did have before

because they think your pretty or hot or whatever and their wondering why some guy hasnt gotten you already. maybe they like you.

it means that he either thinks your a great girl and he most likely wants to be with you or he is wondering if there is anything wrong with you :) :) :)

I agree with Sexton.

Maybe they are interested in dating you

Because they think you are hot and want to know why is that!!

Are you hot?

It's their way of saying, my god you are beautiful and i want you!

..becuz that is the lamest pickup-line they can come up with to talk to you....