Someone asked me that in a bar once while grabbing my ass, and I turned around and, "Sure, let's go!! Right now!! Think you can handle me??!" with a psycho look on my face.
Huh....I tried to make the process more efficient a while back. I simply grabbed their crotch and rubbed their vulva. Oddly...my success rate was less than perfect.
I have had it happen a few times with me with women asking. It usually the same types. 29-35 yrs. old, good shape. I'm totally pumped when a woman has that much confidence to just lay it out there like that.