I (27) started dating this girl (30), who I was living with a couple of months ago and I genuinely really liked her. Our relationship started a bit more intense than I might have liked and that was starting to be a bit triggering. She was also pretty good friends with two of her exes and myself and this girl went to a few events together where they were present, we even hung out together with her exes a couple of times. I was a little concerned about some things regarding their relationship because I was worried she was just using me because she felt sad that they were moving in a few months and she wanted to distract herself from that. She insisted that she wasn't, but as the weeks progressed she ditched me consistently to go help them pack as early as two weeks into the relationship.

Well, come to find out after taking me to these events with these people the time they were spending together was centered around talking about getting back together. Normally, I'm poly, and not terribly jealous so this wouldn't phase me, but they tended to be pretty triggering to be around and they had a fairly unhealthy relationship dynamic together that I didn't really want to participate in. Less than a month after myself and this girl got together, she came to me after once again ditching me to tell me that she was going forward with a platonic partnership with them. I was concerned that this spelled the end of our relationship as I didn't feel comfortable having these folks as my close metas and she was unwilling to hinge. It was messy, and after weeks of trying to make things work, to set boundaries, to do whatever I could to make this a nice, comfortable relationship, she broke up with me. She did it because I was struggling with her unwillingness to hinge, getting upset that she insisted on bringing them up because, in her words "they are too big of a part of my life to not mention".

I had already wanted to break up with her for a while, but since I did genuinely feel something for her, I was sticking it out to see if things settled into something more comfortable once her now partners had moved away.

The whole thing left me feeling bad, not because the relationship didn't work out, but the feeling that I was manipulated, dangled in front of her exes so she could be in the relationship she actually wanted to be in, and dropped for being uncomfortable with the whole thing. For a moment I wondered if I even wanted to continue to pursue multiple relationships, but the moment passed.

So what I'm looking for now is advice on what to look out for in the future, on setting boundaries, on red flags and green flags as I have been talking to a few people and I'm afraid to take the next step only to wind up used again. Thanks!