Boards
Seeing things through windows.
I was just on the top deck of a double decker bus driving past a Methodist Church on the way home from the city centre.
We were crawling past the church cos of heavy traffic, so I looked over and saw a class of people sitting looking at a slide show projection of a man's flabby arse.
Someone was talking in front of it, pointing to it and they were all taking notes. But it was literally just a big fat backside. No anatomical diagrams.
I was laughing my face off but NOBODY ELSE ON THE ENTIRE BUS realised and they just thought I was a psychopath.