To the one with braces, I know how you feel. Don't date anyone with braces cuz those things suck when they hook with each other. Also, it feels really cool to bring your tongue across straight and perfect teeth... you'll see... and make sure your wisdoms get pulled cuz those things screw up everything.

Anyway, to give my input on the subject at hand, I'd say if you work with the girl, it might not be a good idea unless you don't see yourself working there in the near future... but if you're gonna do it no matter what, here's my advice:
Just do it. There's only one lifetime ahead of you and opportunities come and go. Don't let your insecurities get in the way of an awesome possibility that could be your reality if you go for it. Why live a life of "what if?"
As to what to say... it doesn't really matter, in my opinion. I got set up on a blind date with my husband now (unbeknownst to me it was a blind date) and all he said was "Do you have a boyfriend? Coooooool!" Take a deep breath before you do it cuz oxygen deprivation makes people sound and look stupid with the whole brainfart to fainting deal.

GOOD LUCK!