Packing Loco - When you push a little train up your butt like it's a hobby

When you push a little train up your butt like it's a hobby and your butt is the only track you need.

I put a train in my butt and now I'm the king of train butt.

My butt is a train track and I'm the conductor of my own train butt ride.

I told my teacher I was sick, but I was really just trying to get a train in my butt.