"Begging to"?

Love me, hate me
Say what you want about me
But all of the boys and all of the girls are begging to If U Seek Amy
Love me, hate me
But can’t you see what I see?
All of the boys and all of the girls are begging to If U Seek Amy
Love me, hate me
================
Why the 'to' in the 3rd line?

Because it is part of a pun/double entendre. The way she sings it, the line sounds like:

But all of the boys and all of the girls are begging to F-U-C-K me.

The "to" makes perfect sense with that substitution.

Can you elaborate some more?

Let's see:

F-U

Nope, that's about all I can come up with.

Haha just got it

:-)