About two months ago a new girl got hired on at this restaurant i work at. We hit it off instantly and got along very well for the first three or so weeks there. After the first few shifts we ended up hanging out alone. One of those times she even went as far as to show up at the bar a friend/coworker and I went to after work uninvited. She said she just figured we’d be there cause she heard us talking about going. during the conversation she insisted on getting my number and then made sure i had hers too. After my friend/coworker left, her and I sat alone and talked for about an hour after the bar closed till I told her I felt like leaving. there was tons of chemistry. I started to realize that i really liked this girl and was certain she felt the same. My coworkers felt the same also and pushed the idea of us getting involved on me and likely her. The day i decided that i was going to make some sort of move i come to learn she had just started dating another guy a couple of days earlier, whom she is currently still with. It sucked to learn this, but it was my fault for not acting quickly and ultimately it is probably for the best cause dating coworkers usually leads to problems. Fast forward to now and things are just awkward and tense between us and i have no reason why. we still do a little bit of flirting and light verbal sparing, but most of the time it feels as we couldn't carry on a semi-serious five minute conversation to save our lives. Pretty much the only time her and i actually have conversations is when all of us go out to a bar after work. Maybe the alcohol loosens the both of us up? Sometimes I am certain that she not only is no longer interested, but that she just doesn't even like me as a person. Then other times i still think she is as at least slightly intrigued. Her and I still have tons of eye contact, she giggles at my dumb jokes most of the time, and she nearly always is first to offer help when i generally ask for some assistance. Strangely about two weeks ago she went as far as to retract an invitation half way through giving it to go to a concert that she issued to everyone else sitting at the table with us(about 4 or 5 others) after she glanced at her boyfriend while talking to me about it, i have no idea what to think of that. A couple of weeks ago jokingly i called her fat cause she was eating some cake and she flipped her shit and smashed the piece of cake in my face. I was shocked by this cause everyone there jokes around like that and she has said very similar things to me before. To me that seems like something someone would do only if they dislike the person or hold their opinion in high regard. Then that same night she needed a ride to the bar that we always go to after work and asked me for a ride knowing full well she would have to sit side by side in the passenger seat with another co worker. I didn't think anything of it at the time, but she could of gotten a ride with a different girl from work and been comfortable. Also, the times that we do talk she hardly ever talks about her boyfriend, while talking about him with everyone else. I could probably deal with just seeing her a couple of days a week at work, but recently she has started becoming good friends w/ the two coworkers of mine that also happen to be my best friends in this city. So now the tension is coming into my personal life, not just work. I wont lie, I am a little bitter over the way she's acting, not really about her having a bf though. While I am still very attracted to her, all i really want from the situation is a sense of ease back with her and possibly someone that i figure could make a good friend. I almost want to directly approach her on the issue, but I feel that would probably be a very big mistake.