Another girl problem, yay

So this has been bugging me for about the past two months. I've been working with this girl for about 5 months now and around February is when I started to want to be more than just friends. I asked a few people and they said to go for it, so I asked her out and she seemed pretty excited, we did the whole dinner and a movie thing. Thing is, I wasn't sure if SHE thought it was a date so that made me hesitate and stuff... I'm pretty sure I had an opening or two but I didn't pull the trigger and blew it or something. Awkward moment when we're at the car and it looks like she's waiting for me to do something... ends in small talk and a hug. Live and learn I guess.

Anyways, ever since then we've become pretty good friends, go out as a group, do stuff outside of work, etc. Here's the catch though, she still is, and was (during our "date"), involved with her ex somewhat. He was out of the picture, came back into the picture, she's still hung up on him and they constantly get into these fights and then get back together. I've met him once but from what people tell me he's a controlling dick and is incredibly possessive about her. So I kinda took a break and hung back to get a feeling for what was going on with them and kinda put the whole thing out of my mind for a week or so. But this girl will be really flirty and touchy-feely one day(s), then distant the next. And by flirty I mean like... I was sitting on a stool during my break, she comes up sits next to me, and snuggles up with my leg. Then goes from there to sitting infront of me and pretty much leaning back into me. I was more than happy to let her, but at the same time I'm thinking "WTF MIXED SIGNALS!". My emotions were getting pretty yo-yo'd.

My one friend says she's treating me like crap and that she wants to punch her, another friend says he thinks she's really into me and I should just ask her out again, and another says that she's using me and if something was going to happen, it would have already. I think I've been hard core friend-zoned but I want to be sure, but I don't want to have this thing blow up and be really awkward. I really, really like this girl and can't seem to just get her out of my mind, even though that might be the best option. I just really have no clue how to go about this =( What do you guys think?

Ask her out and make a move this time. If she pushes you away than that's that, you'll be in the same position you're in now.

The friend-zone is a myth friend. There is a 'try harder' zone and an 'I'm not attracted to you' zone, but no friend-zone. Seeing as she breaks the touch barrier a lot apparently and you've been on a date I'm gonna go ahead and say it is the previous. Just don't pussyfoot. You know what you want, so go and get it.

Worst case scenario you end up with no girlfriend but also no more being jerked around. Best case scenario you end up getting jerked around, if you know what I'm saying. If you play your cards right you can solve her ex problem without even having to confront it.

Well, I didn't go for it but I found out she's back with her ex 100% and supposedly tons of guys get the wrong idea about her, and she's oblivious to it. Time to move on =( Thanks for the help though guys

HAH.
It's funny because I read your post and wanted to reply: Don't waste your efforts, she is still emotionally tied to this ex and until she has severed ties with him he will probably always be around to interfere with your relationship if you did enter in to one. Most likely you would be used as a tool to make him jealous.
Sometimes I'm just amazing.
Pity it's too late to prove it!

Well done on dodging that bullet sir, life would have been miserable. I hope you'll find a much more worthy woman to invest your efforts in to soon.