I was thinking it would be awesome if there was an achievement for dancing with Anthony, Abigail, Georgiana, etc...

You would get it once you've danced with all of them. :)

only if it was retroactive D:

I accept. It would be great. c:

I've yet to dance with any of them but this would be a good one.

One achievement for each person and then a meta once you've hit them all up?

They're working now. :)

The regular invites don't work though, you need to use the Hastily Written Invitations. I' suggest not wasting yours like I did mine.