I think This is Wrong- Am I Crazy?

I have been with my boyfriend for a few years now. He has a female friend, we can call her G. I don’t mind when my boyfriend has female friends, I have male friends.

When we first started dating he suggested that him and I hang out with G and her boyfriend. I agreed and was excited to meet some more of his friends. Well, about 2 weeks later I had found out that my boyfriends and G had actually had a previous romance. They were intimate with each other. It ended because she chose to be with her current boyfriend over my boyfriend. This hurt him a lot. He was very upset. He had me hang out with this woman before informing me that they had an intimate relationship in which she broke his heart. I told my boyfriend I was uncomfortable being her friend, but I would be nice to her if we saw her. I also told him that it was unfair of him to not tell me about their relationship together before I agreed to hang out with her.

Throughout the next couple years we saw her a couple times, but there was never any effort from her or my boyfriend to hang out regularly. I am an honest person, so I nicely told her once that I knew about their previous relationship and she assured me there were no lingering feelings. Recently she has broken up with the man she chose over my boyfriend. She is moving closer to the area where we live. She has asked me to help her find a job, and keep a lookout for housing for her- I did to be nice. She also has mentioned that now she wants to hang out with my boyfriend and I all the time. She even went as far as suggesting she live with us and split rent.

She is a nice person. I can’t say anything bad about her. She has always been kind to me. BUT I don’t really want to have a relationship with the woman my boyfriend had such feelings for at one time, he slept with her more than once, she broke his heart... and now suddenly she’s single and wants to hang out with us all the time? I think it is very strange. I don’t think my boyfriend would cheat, and he knows how I feel about this. I don’t know how to handle this without being rude to her... it’s just not something I’m comfortable with.