Hell no, do not give in and pay. Unless you want your husband and you to bankroll every careless mistake and financial problem for your family from now until the end of time. And if you pay out the money now I guarantee the next time it's going to $50 grand, because hey you can afford it after all! When your parents want a new bigger house guess who's going to pay for that?

Do you want for you and your husband to simply become a free ATM here? Because that's exactly where this is headed. So it needs to be nipped in the bud right now.

Send your parents a final text telling them a) a gift if very different from being made to pay for someone's else lack of judgement and serious error that could have gotten people killed AND b) their vacation was nowhere near the amount of money this is and c) you and your husband are not the solution to everyone's money problems. And you do not want to hear about this again. Ever.

Also give your husband a heads up on what is going on and why you don't want to give them the money. Do not send them the money behind his back or you will have far, far greater problems within your own marriage and the family you need to put first.

If you need to it may do you wonders to go very low contact/no contact with your family for awhile. They sound incredibly selfish and entitled and it sounds like it was a mistake to ever do anything nice for them in the first place. Something I'd probably make a point of in my emails. Your brother and your family all need to grow up.