Very constipated, the soothing light at the end of your bum hole. s**t's just a freight train coming your way.

The story:

I was driving with AC/DC playing and one of my sons is singing along at the top of his voice in the back seat. When I heard him singing "Dirty deeds, thunder cheeks!" with great gusto I nearly drove off the road with hilarity. I didn't dare ask him what he thought thunder cheeks meant, but sort of visualized a huge bottom....