There's a situation going on with my relationship that I need some help with. A little while ago I met a wonderful woman when I say wonderful this woman is great. She's very beautiful has great conversation and we are very in tune with each other. She has the whole package. We've been dating for six months now and I love her very much and I trust when she tells me she loves me too. The problem is someone from her past has come back into her life which has opened my eyes to a lot of things I didn't know about her. One of the most shocking things I found out about her is that she is bisexual and this person that has come back around is her ex girlfriend. When I found this out I asked her about her past. Seems like they had a very serious relationship and they went through a lot together. They were living together for about a year and a half and were planning on having kids and making a family together. She expressed to me that what they had is long gone and she is focused on me. So I let it go. Time passed by and things started changing between me and my girlfriend and she started coming home later than usual. She did a lot of daydreaming while being affectionate, it was like she was with me, but her mind was somewhere else. Just the other day I came home early from work and the ex-girlfriend was in my house with my girlfriend. When I asked her about that she told me they weren't doing anything. They were just hanging out. I'm not comfortable with their friendship. I mean I trust my woman and everything but it's that. But it's just that doesn't seem right with this. OK. 

So what do you all think and what do you think I should do?