I'm not doubting that they were invited, but if you are a retired person, I'm guessing your kids are a little older. I really do believe these types of "across different classes" invitations happened more often twenty+ years ago.

I think such "marrying up" is happening less frequently than it used to. This is an interesting article from The Financial Times: https://www.ft.com/content/2f0b77da-89d2-11e8-affd-da9960227309

"The IPPR (a UK think tank) also noted a much bigger rise in people marrying within their class. Indeed, it says that, from the 1980s onwards, middle tier jobs were lost, inequality grew and education became more important. And so, “social class began to harden its grip on who people met and subsequently married”.