And lastly I agree that it’s weird and quite sad how many people think the necklace never existed and that this is all an elaborate lie. What horrible experiences you all must have had to be so suspicious
I haven't experienced this, but have seen it often on here. There's even a name for it, "Future faking". The man builds up an experience (birthday weekend away in Paris at a 5* hotel, etc) or a present. Says he's so excited to give it to the woman, describes it in detail, etc, and then it never materialises. He will have a reason/bad luck story why they don't go away, or he doesn't give the gift, and because he spent so much money on it, he can't afford to replace it with something of similar value.
It's to make himself look romantic and generous, that he loves the woman so much he would go to so much trouble/spend so much money, but it's just bad luck that stopped him following through. So the woman falls for it, and stays with him, until after this has happened a few times, and she realises this always happens, and he had no intention of taking her away/giving her the gifts.
There was a thread over the last few weeks, where the OP posted about her partner going on about being excited to propose to her. He went on about it so much (but never proposed at the times OP thought he would, like when they went out for a romantic meal) that OP had got sick of hearing about it.
They'd been together 10 years, and the general consensus was that he doesn't have a ring, and has no intention of proposing. He still hasn't proposed, and has told her she's spoilt it now.
It looks like OP's guy is future faking. OP said she didn't want to add the backstory, because she wanted to know about this specific incident, which makes me think he's done other things to let OP down, which is why she's suspicious about this. If it looks like a duck, and quacks like a duck....