My exboyfriend and I have remained friends for the last 8 months since we broke up. He is currently "seeing" this girl that I despise. I am putting "seeing" in quotes, because though they act like a couple they are adamant that they are not dating. I don't know if this really makes a difference in what I have a question on, but perhaps it may.
My ex, this girl, and me are all coworkers. I hate this situation because I obviously can't avoid them together. I do however try to avoid them together outside of work (which is also difficult as he and I have all the same friends). The ex and I make a point to spend time together once a week, catching up. He's my best friend even with what happened between us.
Being around this girl however makes me really really uncomfortable, as I became aware of the fact she was talking shit about me behind my back at work after I had made an effort to be nice to her, which was me going out of my way. Since then I've decided I'm not going out of my way for her, I will not be nice to her but I will not be mean to her either.
Here is my question - I have been making a huge effort to avoid her, because I just don't want to be put in a weird situation. One of our other coworkers, who I am friends with outside of work, is having a going away party tonight. The ex's girl is NOT friends with her, but we work together so she seems to think she's invited (though no one invited her..). She's going tonight to the party with the ex. I don't know whether I should avoid it and make up some excuse why I can't go or if I should tough it up and risk feeling myself fall apart again.
What would you do? What should I do?