De-lurking
I'm the MoH not the bride but had a question as we build our guest list. I know you aren't supposed to break up social units, but is it considered rude to not invite one person of a family (children are grown adults). For example the parents and two adult children are invited, but the third adult child is not invited.
It doesn't seem like breaking up a social unit as the children are grown up and have moved and established their own lives, but also seems a bit odd for every person in the family to be invited except one.
If it matters, the families have been friends since the children were small and all were invited to each other's weddings in the past. The one child who is not invited is not as close as the other two children were, but there's no bad blood either. They're perfectly civil and friendly when they do see each other.