In my experience . . . it doesn't really matter what's going on in his BPD mind. It's always tempting to wonder, I know.
But you said this was a deal breaker. He knew it. He went anyway. Was this a deal breaker?  :)oes it matter if he had a terrible time, got sick, had lousy weather, or if the kids were a pain in the rear? If this is all true, does it make a difference to you?
. I have nothing to add to this, great advice
Second guessing what he is thinking isn't productive. Even less productive is painting him black and accusing him of manipulation, name calling, etc.
Take the high road.
It's simple. You have a boundary that is about YOU. At this stage it has nothing to do with him
It's simple on paper, but it is not simple or easy in practice. But, I sure wish it were.
It is true, Connect, that ultimately this all about you and your boundary.
I don't think I am wanting to paint him black in letting you know what my take on his messge is. I don't think this guy is all bad and I don't see him that way. I just think he is very, very emotionally immature. I think I'm am trying to keep it real, if doing so is unflattering to him right now, so be it. But I still think my analysis of his message is probably pretty accurate and I do think there is some productivity in getting some real, if unflattering, feedback.
The feedback you are getting regarding emotional manipulation is important only in that... . it's kind of standard operating procedure for how these relationships work. I think there's a learning curve to this, and you are in the middle of a learning curve right now. It's also important because this involves YOU. Manipulation isn't exactly just something someone does to us, like getting high-jacked. It's more complicated than that, but usually, if we are being manipulated successfully, it's because we are participating with it to some degree.
Connect, my ex did this kind of stuff all the time, and then the "
oh I didn't even enjoy it" kind of thing was part of it, for the very reasons I just gave you. It doesn't make the men we loved all black, it makes them very immature. It's a very immature style of relating. This IS a form of manipualation, but really, it's not even all that sophisticated or clever, it's fairly transparent, and it is only manipulation if we buy into it.
I bought into this kind of manipulation and allowed it a lot. As much as I might be angry or rail against his 'manipulations' later when he would just pull another fast one, the true story is this:
I went along with a lot of his manipulations (like this one) not because I didn't see through them myself at some level... . but because it at least gave me some wiggle room to go further into denial instead of staying in radical aceptance abou the man I loved.
Ok he isn't really having a good time. So,that means maybe this really isn't all that bad, maybe his stomach ache even had something to do with me and missing me and knowing how bad this was to do this to me, that this has made him sick. How can I really justify sticking with my original boundary when it wasn't really even a very good trip? If he was sick, then he probably didn't really enjoy his time with the other woman, either.The fact is I often didn't want to stick to my boundaries with my bf because he had some really appealing goodies that I was pretty much addicted to having and keeping my boundary meant giving up the goodies! And I didn't want to! This made me suseptible to some pretty transparent manipulations. You had me at hello, you know? So I would go along with his ridiculous manipulations because on some level, it served me to do that. I went along with manipulations when it served me in some way. But I wasn't as honest with myself and I could have been. I didn't have to reallly own reality or my choices.
He is offering you a crumb that can help both of you sweep this under the rug. It's not a very honest crumb, and while it may give some wiggle room for both of you in this current delimma, the fact is, this will keep happening.
So, stay with him, or break-up with him, or take a break and decide later, or something in between.
You can have whatever boundary you want and change whatever boundary you want at any given time!
This is your life! Your choice! For your own reasons!
Whatever you decide, Connect, what will serve you well, is not fooling yourself. Stay in radical acceptance. Whatever happens on this trip... . this man you love, does this kind of stuff, cause he's really pretty emotionally immature. That's radical acceptance.
It has nothing to do with you or the other woman, it's just that he's really very immature and will be immature this way for a long time.
And knowing that, you get to decide! Just stay honest with yourself, it will serve you well no matter what you decide.