Ladies / Gents: What should be my next move?

So, here's the deal.

I've had my eye on this really beautiful girl at work for awhile now. Anytime we've crossed paths, I would try to make eye-contact with her then say hello, but she'd never look at me. From a distance, she'd smile and joke with her friends, then as I'd approach, she'd get serious (all of a sudden). So, I figured maybe she's not interested.

Last Wednesday, I'm chatting with a mutual friend, and mention to her (how pretty I think her friend is and how mature she seems) "I wonder how old she is?". Our mutual friend says she will talk to her and then get back to me.

The next day, my friend tells me that I'm her friends "type" and she wants to know how old I am as well. She told me that she didn't even mention my name to her but she was able to guess it was me on the first try, because I am her type. She said her friend was smiling left and right. When she told me that, I starting smiling uncontrollably.

So, after-work, I'm getting scanned out by security (I work at a retail store) as I'm leaving the job, I see the girl about to leave as well (we make brief eye-contact) so I say to myself, let me make my move now. I walk out of the building to wait for her.

All of a sudden, this guy I've never seen before walks out the store. He stands about 3 yards away from me and starts to look inside the store. I'm doing the same thing, and I'm wondering: "Are we both waiting for her?". I'm looking at the guy, but he doesn't look back. When she finally walks out the job, he walks towards her and at this point I know they're together, because he starts carrying her bags and is walking with her.

Luckily, two of my co-workers walk out right behind her, so I don't look like a complete idiot. I chat it up with them for a minute, then we all go our separate ways.

The next day, I tell our mutual friend what happened and I ask her if that was the girl's boyfriend? She said that it might have been, but the girl told her they had broken up sometime last month. She told me that she can't stand that guy because he treats her friend so bad. I'm like if he treats her so bad, then why is she still with him?

I've been through this before, and I'm not trying to go through it again. I told my friend to talk to her and find out for sure what the situation is. That was on Friday. On Sunday I talked to my friend, but she forgot to ask the girl about what happened.

I'm starting to lose it here. I really like this girl, and now that I know she is interested as well, I need to know what's going on. I don't want to wait too long, but I don't want to push the issue.

Everyone's feedback is appreciated, but I'm very interested on the female's POV.