I know it's prison slang, but I wonder about the origin

[substitute]

Does anyone know why “Sancho” means the Other Guy? Specifically, the man who takes advantage of your time in jail to get it on with your girlfriend or wife?

My only association with that name is Cervantes, and I don’t recall Sancho Panza being a dangerous ladies’ man, but it’s been years since I read it.

Comments

[gynocide.livejournal.com]

I don't know where it came from. The first time I heard the word was in Sublime's Santeria song. I named my cat Sancho and I didn't know what it meant, but it's already stuck. Besides, it's funny when people yell "Sancho, where are you? Aren't you hungry?" out the backdoor.

things that make you go hmmmm

[amorpoeta.livejournal.com]

Well it's my understanding that it is from Sancho Panza. Mr. Panza was a sidekick. Therefore the sidekick to a neglected wife would be her "sancho". All speculation though.