When grandkids ask innocent questions, such as “why can”t I come to your house?” or
“how come you didn’t come over on Christmas?” be careful how you respond. The less said the better. Providing too much information in the way of an explanation could backfire.
If you tell the child, “well, I did invite you over, but mommy said that you were busy” or “I tried to stop by on Christmas but no one called me back”, then there is a good chance that the child will confront the parent. You want to convey to the child that it wasn’t your doing so that they know that you want to see them but when they pass on the reason to the parent it looks like a conspiracy.
A better response is “I understand that you want to come over, it’s up to mommy.” and
“Sometimes it doesn’t work out that everyone can get together on Xmas Day, so this way we can celebrate an extra sort of like two Xmases.”