My fiancés parents...

Ok they are the sweetest. I've met them and spent tons of time with them.

Long story short, my parents really want to meet his parents and wanna have them over for dinner at some point. They want a nice quiet dinner to just get to know them a little. My mom has mentioned that to both me and my fiancé twice casually and most recently asked about a specific evening having them over for dinner.

In private, my fiancé said that his parents won't come to my parents for dinner unless my parents allow his siblings (he has four) their spouses (two are married) and their children (there are 3 kids) to come as well. It's all of them or none of them.

And I'm a little confused, my fiance is just the messenger I know. But I'm sensing that maybe his parents don't really want to meet mine?

I dont come from a big family. My family isn't super well of financially either and I know my parents. They can't put a spread on for 16 people. They live in a condo. Like?

How do I tell my parents that his parents won't come unless everyone They want there comes?????

I feel like ugh this is how it begins our lives together with our families being....difficult. Like if you were able to, wouldn't you maybe wanna meet your child's future family??