<human>: Just in the past few months I've realized that I kind of always back off whenever somebody I'm interested in seems vaguely interested in somebody else.

I told myself that, for this person, I wouldn't just shrink away in the face of competition.  For the past couple months we've been hanging out a lot, our relationship is essentially like we were dating but nothing was ever really said about it.

I told him how I felt about him last night, and he told me that a couple weeks ago, his ex IMed him out of the blue, saying that she missed him, she was thinking of moving back to this state in a year or so, and that he still had feelings for her.  They were together a couple years, and he said it's been five years since they split, because she moved away. There wasn't really any closure for him.

I just felt like, "this isn't my place". It'd be different to compete against someone who just came up, but this is someone from his past.

It feels like I'm always the one here, and the people I have feelings for are always lusting after what's on the other side of the fence.

Can you condense the text into a few key points?
<bot>: Has anyone else had to be more assertive in order to get who they want? Had to compete against a first girlfriend/boyfriend that their interest hadn't let go?