If you actually like her, in that "I could eventually marry this girl and live with her as my wife for 58 gloriously happy years until we both die of old age..." then I say Fuck it, ask her out!
You were just two co-workers joking with each other. I doubt they'd fire you over something as insignificant as that. If they would, fight them. As long as you're not crawling around the office on all fours, grabbing at the women's feet and licking them while they work (I'D fire someone for that!) or creepily staring at their feet while they are on break.
I guess I'm getting fed up with this tight-ass terrified political correctness that has enslaved the American population. We in this country need to grow the hell up and act like adults. Sexual harassment rules and laws made perfect sense when it was to defend women from having to fuck their butt-ugly boss to get any kind of raise or promotion, or coffee break. But when it got to the "you can't even tell your workers their brand new outfits or hair do's look nice," it got absurd. I've decided to say "Fuck it!" and be the person I am, and I have yet to run into trouble. I deal with janitors to average workers to high ups, to very high ups. They all like me. I'll use sex humor around the president's secretary, and she laughs and loves it. I'll talk about pretty girls to the big wigs I'm cool with, ....and usually they agree! You kind of scope it out first, and I'm not some raving pervert, so they all know who I am and are cool with it. I think because I'm someone who isn't fake at all, but am actually genuinely nice to them. I think they subconsiously know that if they were ever down and out, I'd still be as nice to them as I am now since I'm so rough around the edges, and they know I'm not brown nosing.
Millions upon millions of people have met their significant others at the workplace. They can't stop people from hooking up at work, and I'm sure you win that lawsuit if all you did was ask a co-worker out, or make some minor reference to giving a foot massage to a worker with hurting feet. Jesus. The people who get folks in trouble for that stuff are the bitchy, anal workers anyway, so just make sure she's not one of those. (Kind of like, there are cops, then asshole cops. If you drive under a yellow light, and it turns red when your bumper is still in the intersection, a normal cop could care less, but an asshole cop will pull you over and give you a ticket. And actually, my normal cop friends all hate asshole cops!)