I certainly don't know anyone who doesn't know the meaning of this phrase. Even my Chinese girlfriend, who has only been an American citizen for two years, knew what it meant, and was offended that I would even ask her such a question. Roberts is an adult male, he knew exactly what he was sayin'!
Your girlfriend was offended you asked her a question that wasn't even personal? Better tread lightly here, freeper, lest you become entangled with someone who is suffering from terminal pc.
Well, since I posted I've asked 4 people about it. The 2 men knew it. The 2 women, one 25 and one 47, did not.
I've never in my life heard it before and I grew up with 5 brothers.