When threats backfire

Spencer has been singing Christmas carols non-stop. It is awful and horrible to be making dinner to a serenade of "Jingle Bells" on the 17th of January! We went on a family walk and there is a house in our neighborhood that this has their Christmas decorations up- we are talking massive, Griswald style decorations. I was at my whits end when Spencer started another round of "We wish you a Merry Christmas" when I said, " If you sing another carol again tonight I will get in the car and drive you to the Christmas house and make you sing for them- they are the ONLY people who still want to hear Christmas carols."
It worked for Spencer, not another peep out of him the rest of the night, but Kathryn cried and cried because she WANTED to go to the Christmas house and sing for them. Everyday since she has woken up and asked if she can go and sing to them with lots of tears when the answer is no.