See the Tree, the Happy, Happy Tree.
I used to insist we watch Its a Wonderful Life while we put it up. Then I saw Lincoln's little 4 year old ears catch the scene where Mary yells up to her mother, who had disdainfully asked what George wanted. She answers, "He's making violent love to me mother."
Oh. Um. OK. How had I missed that line all these years? There are just certain topics that should not be chatted about whilst decorating the tree. Save your making out for under the mistletoe ok?