The topic of a spider in a urinal comes up on Christmas.

A dialogue on opening a present:

"This has the story of the spider in the urinal."

"Very few Christmas families are talking about a spider in a urinal.... Wait a minute."

"She's blogging."

"She stops Christmas to blog."

Here's how the chapter "Birth Death, and the Meaning of Life," in this book, begins, on page 208:

One summer more than ten years ago, when I taught at Princeton, a large spider appeared in the urinal of the men's room of 1879 Hall, a buiding that houses the Philosophy Department.