“Do someone a favor and it becomes your job”

“Do someone a favor and it becomes your job” is a jocular work saying. If you help someone out, then it will quickly become your job to always help out. “Do Someone a Favor and It Becomes Your Job” was the title of a 1988 episode of the television series Murphy’s Law. The book The Complete Murphy’s Law (1991) by Arthur Bloch included the saying as “Pinto’s Law,” but it was not explained who Pinto is.
 
The saying has been printed on a coffee mug and an e-card.
 
   
The Internet Movie Database
Murphy’s Law (TV Series)
Do Someone a Favor and It Becomes Your Job (1988) 
Lee Goldberg ... (staff writer)
William Rabkin ... (staff writer)
Lee David Zlotoff ... (created by)
 
Google Books
The Complete Murphy’s Law:
A Definitive Collection
By Arthur Bloch
Los Angeles, CA : Price Stern Sloan
1991
Pg. 151:
PINTO’S LAW:
Do someone a favor and it becomes your job.
 
Google Groups: rec.arts.sf.fandom
AKICIF: moving phone numbers
Kip Williams
6/18/03
This has echoes of a maxim I once heard and took to heart: “Do somebody a favor and it becomes your job.”
 
Google Books
Soldier Boys
BY Deirdre Savoy
Mira Loma, CA: Parker Pub.: distributed by Book Masters
2008
Pg. 19:
But as the saying goes, do someone a favor and it becomes your job.
 
Amazon.com (UK)
Do someone a favor and it becomes your job. - Funny Printed Coffee Mug [BLK4371]
by Mugz Game
Date first available at Amazon.co.uk: 14 Sep 2011
 
Twitter
Cameron Morrissey
‏@ManagersDiary
DAILY WORK HUMOR - Do someone a favor and it becomes your job.
2:27 PM - 13 Apr 2014