In my experience; i have heard all kind of things.
Things like:
Dude, you really cant dance.
or I never met a guy who dances all night, usual they are just standing or sit at the bar.
And some girls asked if i was a dance instructor (supose that was her opener

)
What i do is look around, you know look what other guys do a night before, or watch some mtv, well pick out the easy moves that is or practice some.
My aditude if i am dancing is like: I dont care what other people think, I am having fun with a big smile on my face, making eye contact here and there, sort of showing some positive energy.
Succes if you guys can read my english haha