My Son Gave Our Mother-Son Waltz to His Fiancee's Mother — So I Said She Could Sign for the Venue Too

"My mother-in-law will dance the mother-son waltz. She looks better in photos and honestly, she earned it," my son said a week before the wedding. I said: "How lovely. Then she can sign for the venue too." The bride looked at him: "Sign for what?" And the form in my purse still had a blank line at the bottom...