At the office Christmas party, a co-worker from another department was flirting with me and then invited me out to a bar afterwards. I said I'd go and then just didn't show up as I was in a relationship and the bar was way too crowded. She basically pretends I'm not there when we pass each other in the office, (as she took it as a rejection). But I'd like to make it less awkward and would like to hang out with her, even as just friends. What can I say in this situation? It's been a while since the party so I can't really bring it up without it being very out of place. Should I just say "Hello again"?

This isn't necessarily me wanting to fuck her, I honestly just kind of want to be her friend as she was fun to talk to. I'm just really awkward sometimes and handled the situation poorly.