If there are cousins for your children to know I would go esp as you say you have missed other events. When I plan things now I think if my kids and put them first. I figure if I am dead and gone at lest I have nurtured family relationships.

Op, you are allowed a preference. Make a decision. You owe no one an explanation beyond, " I'm so sorry, we already have vacation plans" A little explanation helps so no one thinks it's a frivolous decision but too much blah, blah, blah, details revealed and public angst about it, is just inviting drama, and unnecessary advice.

Don't feel bad saying no. People understand that it is difficult and expensive to travel with small kids, and they probably won't be surprised if you can't be there. If you're close to the relatives and you want to go, think about going on your own! I'm sure your DH can take care of the kids on his own for a couple days. That cuts down significantly on the cost, and you get to see your family.

I might dissent here and encourage you to go. Extended families rarely get together except for weddings and funerals. It's MUCH more fun to see everyone at a wedding than at a funeral. Have they even met your kids? It seems like a nice opportunity to get everyone together.

Now obviously if you can't afford it, you shouldn't go into debt to make it happen. Could you think about just you going? Or you and your DH, if someone else can watch your kids for the weekend?

You do not HAVE to attend any wedding. But if you like/love this family, when else are you going to visit with them in the next 10 years?

There's a good chance they already had you pegged in the "Invited, but not likely to accept" category when they sent out the invitation. I know when we planned our wedding, we invited folks that we would have been happy to see, but didn't really expect to come for various reasons (health, age, cost, family duties etc.). Beyond that, I don't think you need to provide any reason for the decline...as others recommended, send a present.

If you really feel bad about missing out on the wedding, could you consider going solo to save on cost? Say the kids and husband are booked, but head out yourself?

I wouldn't even say why I can't make it.

"Sorry we can't make it ... but here are a few $$ for you to enjoy as you please". End of the story.

Don't feel bad about skipping any Monday wedding...wth.