Men do not want to bang every female acquaintance they come across, no matter what the hype currently is. That is a sad existence if he is lying in the bushes like a lion stalking prey, waiting for a chance to get some action from her. If they are really trying to go there with them, it's better to lay cards on the table. Male/female platonic relationships are cool when boundaries are clearly established and enforced. I have a female best friend that means more to me than the average woman. For a while, I had dates who couldn't accept I didn't want to fuck my friend. I reminded them on their way out the door that they wouldn't be there with me had I chosen my friend. Only my wife accepted her and it was never an issue on either part. It's essential for your own sanity AND the health of any romantic relationship that any platonic friend be held in proper perspective at ALL TIMES.
Those work relationships are difficult, too. Working so closely with one person can set the tone for dangerous things if not monitored properly.
"He who is not courageous enough to take risks will accomplish nothing in life." - Muhammad Ali