If you had children from a previous relationship and a child with your current spouse and you heard a telephone call between your spouse and their parents asking if they could meet at a local attraction at some point soon but specifically asking not to bring your older children so they could spend some time with their grandchild.
We tend to do lots together so the older kids tend to come along a lot when we meet with spouses parents. Older kids really like spouses parents too although don't call them grandparents.
They were 4 & 6 when we met.
YABU - there's nothing hurtful in this conversation.
YANBU - I'd be hurt and would say something.