Eric Lippert takes a short break from his usual barrage of mind-melting in-depth technical articles to provide a short article on genealogy, wherein he explains the simple system for naming cousin-hood and removed-ness in English.

This was all fairly straightforward, until he linked to a mind-melting video of a country singer asserting that he is his own grandfather, complete with an accompanying family tree diagram that updates as the song progresses to help you keep track of the facts:

So I guess the moral of the story is that directed graphs should ideally be kept acyclic if at all possible?