OP you have kids, if you did the same would you expect things to be the same between you afterwards?
My dad did similar to me with a flat deposit and literally saw me go without food to pay him back. It wasn’t for a mortgage it was for a rental deposit and a month upfront and was definitely offered as a gift, he knew how much I’d struggle to pay it back and didn’t need the money.
The relationship will never recover now, my dad has been dead 11 years and I still feel so much anger over it, if I’d known it wasn’t a gift I’d have saved longer and wouldn’t have spent the following year with no heating on and eating plain pasta and walking two miles to work and back in the rain because I couldn’t even afford the bus.
This was after giving my sister thousands as an actual gift but that’s a separate issue.
I’m in therapy and this is something that I spent quite a lot of time trying to get past, even if you pay back the money and try to stay on good terms you will resent the deception and struggling to find money so your parents can blow it on a cruise!
Please don’t give your parents any money, you will honestly hate them more in the future then if you stay firm and say no now. If you are forced to struggle whilst handing over money you didn’t ask for then you will become more and more angry and bitter. Fair enough if they desperately needed it but they are asking you to struggle so they can spend it lavishly without a second thought for you.
If you just say no and you don’t have it now then it might result in an falling out but that might be possible to come back from if you can get them to understand your point of view. If they don’t now then they might in the future but even if you do end up falling out then you will know that you were in the right - as this thread proves to you.
If you do pay it you’ll have a long period of time where you will struggle to pay it back and you might have a surface level relationship but underneath that bitterness and resentment will build and you’ll also be angry at yourself for allowing yourself to be treated in this way. You will see your kids going short whilst your parents don’t care and show you holiday photos, there is no way any relationship can survive this.
There is also the fact your husband will feel similar anger and that’s going to put strain on your relationship with each other.
Put your husband and kids first, they don’t deserve to come second to your greedy grabbing parents who used your wedding to show off.
I know it hurts, it’s fucking sickening and you have my complete sympathy. The way to solve this isn’t by giving money though, I’d do what a pp suggested and show them this thread.