We Wish You A Merry Christmas" is an English folk song from the 1500s and is the remnant of a time when poor carolers would hit up wealthy listeners for handouts. It's a cheeky tune which recognizes the dynamic between rich and poor, calling for figgy pudding and refusing to leave the wealthy person's doorstep until some is delivered "right here." This is an awfully ardent demand for a Christmas song, so it's meant to be sung with a certain degree of joshing.