Hey Santa!

Odd but true fact: my brother and I often call each other "Santa."

I recall reading that the novelist Walker Percy and a friend of his used to call each other "Rollo"; apart from that, I've never heard of two people calling each other by the same nickname.

Origin of the practice: back when I was a twenty-something, we went to a theater in Madison, and it must've been shortly before Christmas, because there was a commercial before the movie where these elves were saying to Santa Claus, "Hey Santa, want a Coke?" Somehow we twisted this to, "Hey Santa, want some Jonestown punch?" And from there to calling each other "Santa."