Ok need a bit of advice here so sorry if the post is long.

Every sunday myself and some of my friends who all work together (barring myself) go to our local pub to have a drink and laugh, now I while back I started dating one of the girls who goes and things went really well or a bit but we argued a lot, mainly due to my own insecurities.

After one particular argument she decided she wanted to "just be friends" the three worst words a man can possibly ever hear, but then I find out that its most likely just an excuse as her ex boyfriend who shes apparently obsessed with came back on the scene, so we argued about that for a bit etc... then I told her that I wont be texting her ever again and that I'm deleting her from facebook etc... Ive done very well for 6 weeks with no contact even when she texted me asking if we were friends yet because she wanted to come out with the group as normal.

Now without my reply she decided to come anyway, I ignored her all night, barely even glanced in her direction, but apparently she was annoyed that I paid her no attention and even tried to stop other girls in the group from talking to me.

Now this week I find out shes bringing her boyfriend along.. which angered me because its a really low blow to either get my attention, get a rise out of me, or generally piss me off.

Now my main question if I do decide to go, how do I act? Does anyone have any tips on how to play it cool and perhaps get her at her own game, or should I stay well clear and give this week a miss and not get sucked into her patheticness?

If anyone has any other tips for my situation it would be really appreciated, I must admit I fell hard for her and I'm still not completely over her but I'm getting there.

Sorry for the long post guys, and if this is in the wrong section feel free to move it MODS.