YOUR BEST FRIEND'S MAN
Usually this one is a self-esteem issue, on both parts. You don't feel that you're good enough to have your own man, and the friend doesn't feel she deserves a whole man to herself.
THE SUAVE CO-WORKER
He comes to work well groomed and smelling nice. You've told him everything about you, so he knows what makes you tick. Besides the obvious pros and cons. Spending that much time together can be a timebomb ticking. If the relationship doesn't work out, you are still left working in the same environment with this person to whom you are still emotionally attached.
Nuff said....Don't forget the reason why he's your EX!