That's what I mean Butt, beforehand they were a bit star-gazey and now they're pointedly not if you see what I mean?
Please don't think that my thoughts count for anything but your thread has made me a bit uneasy because I know how these things can quickly slide out of control.
Your partner seems a bit of an adept 'handler' of you - and I'm getting that from what you've posted, what you've said about his responses to you - he's tricky. In your mind (from what you've posted), he's a bit of an 'innocent' and 'genuine' but if he were that, he'd have said to you by now, "Butt, I've been an arse, and I'm sorry, you mean more", but he's not doing that.
He's treating you the same as he always has - but he knows that he's changed things lately, made you unhappy and wrong-footed because of his behaviour with this woman. If he were innocent, genuine - or sorry - he'd be showing you that, and he isn't, is he?
I don't know about this other woman (I won't refer to her as an OW because she's not - so far), she may be very uncomfortable with your partner's attentions - or she may be complicit and happily egging him on or at least participating willingly.
What I meant by 'he's not vacillating' is that he's already done the star-gazey thing and either it's worked for him or it hasn't - but he's still not making you feel as if you're the only woman in his life - and you'd think he'd be doing that.
If I were in your shoes (and I have been), I'd have my Plan B, my 'war chest' all ready. You may never need it but this man isn't making me feel confident for your future with him. You deserve somebody who doesn't cause you to post anguished threads about your relationship. You really do sound very nice, Butt, and strong too.
Ask your friend for her views from YOUR perspective, if she were in YOUR shoes, viewing their interactions, how would she feel? You obviously trust her so ask her. She knows your partner and she knows this other woman - and she knows you. That's more than any of us here can know and it's really easy for posters to blithely post based on nothing more than nuances because we're not at the sharp end - you are.
If you're tired then it must be even harder to take all this in, have to deal with all this on top of your day-to-day stuff. I know it sounds trite but if you can have a bath and get an early-ish night, it might be the best thing for you right now. Read again tomorrow and maybe speak to your friend - when you've had a refreshing sleep - I just can't emphasise that enough, being sleep-deprived is horrendous.
I'm really sorry for your situation, Butt and I really don't want to give you extra worries; I could be completely off base, easily done on threads where you can't see/speak to the other person.