BACKGROUND:
I dated a girl for 5 yrs and broke up due to the long distance college thing....eventually got a new gf with unknown complications attached (i.e. before we started dating she booked a ticket to visit her ex and end of next week will determine whether or not we are staying together)

SCENARIO:
however same old story as countless other people goes on...not sure if I am over my ex....she currently has a bf and I have not spoken to her for a while. (Do not want to appear weak or that I want her back, rather want her to approach me) Anyways my family is very good friends with hers and what do you know...invited them over to a party in 5 weeks. It will be the first time ive seen her since my birthday (she drove 2 hrs to visit me for my 21st in June, last time i saw her) I also tried talking to her a little bit through txts but she mainly replied in short txts as if not wanting to talk. Also, she never texted me so I was always initiating it. After a few days of that I stopped and last time I texted her was on her bday which she replied thanking me and not wanting to continue the conversation.

PROBLEM:
I do not know how to act when I encounter her and her family. Things with my current gf are going well and even with this ex occurrence it is likely nothing will happen and we shall still be together. So as I see it 2 scenarios can play out at the party, my gf will be there or i will be single and my gf won't be there. Most likely my ex will not bring her current bf. And it will be likely my ex will probably hangout with me and my friends since there really isn't anyone else for her to hang out.

NEED ADVICE FOR:
I am not sure what to do in this scenario. Though I may think I may still care for her and may want to be with her one day I am not sure that is entirely true. The current gf scenario is on the rocks due to mainly her ex. Do not know why I am putting up with this mostly guess I feel my game is weak and do not come across many women I am interested in or are interested in me. Any advice is appreciated.

"When you live for a strong purpose, then hard work isn’t an option. It’s a necessity"~ Steve Pavlina