Just to update on this: T-Day has come and gone. Prior to that, the full disclosure of relationship structure had been covered, so when the parents were over, they knew who everyone was.
It went great! They were gracious, engaged, curious and personable. Very pro the happiness and stability that this relationship has brought across the board, particularly to their granddaughter. We're all having dinner again this evening before they leave town. In particular, I really appreciated the way they drew my daughter out, since she was pretty shy with these new people.
Given that we're talking about a Catholic and a Mormon, I was prepared for a much more dramatic response. To have such a warm reception was a very pleasant surprise! Still, I'm glad it's over... ;)
Now, I'm in a space where I want to get to know them better, but don't think that there will be time to make that happen much. It would be great to have some time without the kids around for a more frank conversation. Ah well, I guess it will need to be a more incremental approach.
Yes, I like them. What a relief!