DH wants to meet up with his ex while abroad with work

I'm so glad I'm single and can keep my friends. What suffocating marriages most you lead

Yes, it's odd, the Insta thing. The coolwife sorority will be along to explain why that's not true shortly (they probably already have). But it is, indeed, odd.

I find it weird you extend your stay, more times than I can recall hubby as soon as his work is done has flown back and surprised us all because he wanted to be back with his family

Well he obviously is still invested in her to some extent if he still follows her on Instagram. I'm quite surprised you seem so ok with that.
If he used to live in Paris it's understandable him being nostalgic about being there and wanting to extend his stay over the weekend. But including his ex in his nostalgia is unreasonable. And I think you should ask him not to.

To add, the fact that he’s asked you about it means he knows there’s a reason he needs to ask, and therefore he shouldn’t even ask or consider it.

If my DP had been away with work for 2 weeks, he’d be wanting to get home to me and our DS, not extending his trip. And certainly not extending his trip and meeting up with an ex.

I think this is outrageous, personally. I know people often feel pressure to be “cool” about some things, but this is too far for me.

They are both married now. If her invitation was to go out with her and her husband, or to go to their home where they would both be, I wouldn’t have a problem. Just the two of them? No, even if I was 100% certain of no cheating, it would still make me very uncomfortable. It feels disrespectful to your marriage.

You don't want him to, so ask him not to. He will understand completely the reasons even if he pretends not to.

If he insists or gets in any way stroppy you know you have a huge problem.

You aren't wrong for feeling as you do but honestly if he's a decent man and you trust him then personally I'd let him.
I let my husband meet up for coffee with his ex when he was in her city for other reasons once.. well let is the wrong word, he's a grown man.. I mean I knew about it and didn't voice any objection.
I understand she was a friend and a big part of his life so when he was in the area he wanted to see her. If he still wanted to be with her he would be. But he's not.. that relationship ended. End of the day I don't expect people to stop caring about people they used to love. I certainly don't.

As your dhs ex lives in a completely different country it's not likely things are going to start up again between them! And imo if someone's gonna cheat they are gonna cheat anyway it doesn't matter what rules you have about who they can and can't see.. because not cheating comes from within that person not your enforced boundaries. It's a choice.
So personally I do not try and say who my DH should and shouldn't see. And I wouldn't tolerate that the other way round either.
We've been together many years and I love him and trust he loves me.
Of course it's up to you how you navigate your own relationship but that's just my opinion.. I'd not be trying to prevent this. I'd understand. I have exes that live far away that I'd try and catch up with if ever I was travelling near them. I certainly would never cheat on my DH and am not unhappy in my marriage.

I haven't voted OP, because it's hard to know if you're being unreasonable, as we don't know your DH. Has he ever been unfaithful to you? Has his physical appearance changed much since he was with her, ie, has he lost all his hair, or gained a huge amount of weight, something which might well put her off if she were looking to re-kindle the relationship? Have you seen a picture of her as she was, and an up to date picture of her, in order to tell if she's changed much physically since he was with her? At the end of the day, only you really know if there's a chance he might be tempted. Have you told him that you feel a little uncomfortable at the thought of them meeting up, and if so, what sort of response did you get, was it reassuring, or did it not make a difference? Finally, you can't do anything to stop him meeting up with her if he really wants to, as he could just do it, and lie, so I guess in your shoes, I'd tell him I feel a bit uncomfortable with it, but if he really wants to see her, you can't stop him, so it's up to him.

Well, you’re not in a position to “allow” anything but you need to speak to him about how you feel. It is possible he has no idea how much it would upset you and would cancel in a heartbeat if he knew.

Also, after two weeks away, he should be dying to get home, not extending his trip.

Not just the 2 of them, no...its a bad idea imo

I’d put my foot down on this OP sorry 🙈 as you say maybe in a group setting! But just the two of them!? Absolutely not