<human>: Can you provide a brief rundown of the text in within 3 sentences?

Didn't happen today, 24 years ago actually. I have a pretty good sized family with my mom having 5 siblings so family gatherings are pretty packed. It was a few days before Christmas and my Uncle and his wife had just bought a new house. Having a lots of room, they hosted our family Christmas.
I was 3, my cousin was 3, and Batman was the shit. 
My cousin and I had the Christmas spirit. This was our favorite Christmas song:

Jingle Bells

Batman Smells

Robin laid an egg

Batmobile lost its wheel

and the Joker got away

Batman's in the kitchen

Robin's in the hall

Joker's in the bathroom,

peeing on the wall.

We took it a little too literally and peed on the bathroom walls of my Uncle's new house. We both took quite a beating and now, every year, we're shamefully reminded of 3 year old self's FU.
<bot>: 3 year old cousin and 3 year old me sang alternate Jingle Bells and peed on the walls of my Uncle's new house.