Originally posted in chat, but reporting here as is a far more appropriate place:
DP was a bit pissed when he came home last night, and we were talking about his age, and that he is going to be 39 in a few months time. He then said, "(male friend) is going to be 39 later this month. (ex partner) is going to be 40". I was taken aback by this, but as he was pissed, I just went to bed and decided to ask him about it tonight instead.
To put this in context - he and his exP were together for a decade. A few years after they broke up, he and I got together. They were supposedly 'friends' at this stage, although a 'friend' wouldn't have refused to see his current partner (me); she was still very angry about their break up, and he felt very guilty about it. 18 months into my relationship with him, he got very drunk when out with her, slept with her, and left me. After a couple of weeks he told her he'd made a mistake and wanted me back, and eventually (after lots of humming and hawing on my part) we got back together.
Part of the deal is no contact, which he says he understands and is fine with, as he knows what he did was shitty and horrible. This is why I find it so odd that so long after all this happened (the cheating on me bit was three years ago), he casually mentions her turning 40 to me. He mentioned her in another context a month or so ago, which also surprised me, as we don't talk about her. It suggests to me that he must think about her quite a bit - otherwise she wouldn't spring to his mind.
I know I can't police his thoughts, and I don't want to. I am just concerned. It seems odd. Doesn't it?