“Why do Mexicans eat beans for dinner?”/“So they can have bubble baths.”

A beans-make-you-fart joke is:
 
Q: Why do Mexicans eat beans for dinner?
A: So they can have bubble baths later.
 
The joke—sometimes regarded as offensive—has been cited in print since at least the 1980s.
 
     
Google Books
Totally Gross Jokes
By Julius Alvin
New York, NY: Kensington Pub.
1987, ©1983
Pg. 17:
Why do Mexicans eat beans for dinner?
So later on in the evening they can take bubble baths.
 
Google Groups: alt.tasteless.jokes
Farts
.(JavaScript must be enabled to view this email address)
2/5/96
(...)
Q.      Why do Mexicans eat beans?
A.      So they can have bubble baths at nights.
 
Google Groups: alt.tasteless.jokes
mexican jokes
Laura Schooler
5/26/96
(...)
Q. Why Do Mexicans Eat Beans For Dinner?
A. So They Can Take Bubble Baths.
 
Google Groups: alt.pro-wrestling.wwf
Why do Brits eat beans on Friday?
TekG0525
5/6/02
So they can take bubble baths on Saturday..LOLOLO
 
Twitter
PantherAR
‏@pantherar
@tuffarmywife cept they didn’t have bubble baths unless u ate beans 😊@coyotehaven007
3:13 PM - 26 Oct 2011
 
Twitter
Erica Adriana Jones
‏@EricaMexyJones
Why do Mexicans eat beans during the day? So they can have bubble baths at night…
2:09 PM - 11 Jun 2012
 
Twitter
El Chapo
‏@Hinojosa14_
Why do Mexicans eat beans for dinner?so they could have bubble baths cx
7:29 PM - 17 Aug 2013
 
Twitter
Anita Morgan
‏@AnitaSMorgan
Why do Mexicans eat beans for dinner? So they can have bubble baths. #TGoniTunes
8:53 PM - 10 Sep 2013
 
Google Books
Food Jokes
By Jeo King
Marine Publishing
2016
Pg. ?:
Q: Why do Mexicans eat beans for dinner?
A: So they can take bubble baths
 
Twitter
s. oph
‏@s00phs
@Dannygage97 why do Mexicans eat beans for tea?
so they can have bubble baths later on.

🚬🚬🚬🚬🚬🚬
6:14 PM - 3 Sep 2016
 
Reddit—Jokes
Why do Mexicans eat beans for dinner?
submitted February 26, 2017 by Parkatr0n
So they can have bubble baths.