We have an advent calendar that we do every year.  Each day it has a different activity that we get to do.  One of those activities is to sleep under the tree.  The kids are always super excited to do this.

They cant actually sleep under the tree but they have fun camping out next to it.  We stayed up and ate popcorn and watched a Christmas movie.

Then the kids went to bed next to the tree, while Greg and I slept snugly in our bed.