“You can’t ride two horses at one time” is a popular proverb that dates to at least the 1800s. The expression slowly become more colorful. “We cannot ride two horses with one seat” was printed in the New York (NY) Times on September 18, 1926. “You can’t ride two horses with one arse!” was printed in Penthouse magazine in 1968.
   
“And she (Aunt Rose—ed.) used to say, ‘You can’t ride two horses with one behind’” was said by actor-director Woody Allen in the movie Broadway Danny Rose (1984). “You can’t ride two horses with one ass” was said in the movie Sweet Home Alabama (2002).
   
“You can’t ride two horses with one tuchas. YIDDISH PROVERB” was printed in the book Where There’s Smoke, There’s Salmon: The Book of Jewish Proverbs (2001) by Michael Graubart Levin.
   
             
9 April 1878, Janesville (WI) Gazette, pg. 1, col. 2:
In other words, the Journal can’t ride two horses at one time while each is going in opposite directions.
 
18 September 1926, New York (NY) Times, “Letters,” pg. 14, col. 8:
We cannot ride two horses with one seat.
(...)
KATHRYN MAJOR.
New York, Sept. 16, 1926.
 
Google Books
Proceedings
Pennsylvania Gas Association
1960
Pg. 50:
If that be the case, I can only express my regret for I believe what I believe and I speak my convictions, and you can’t ride two horses with one carcass.
     
Google Books
Penthouse
Volume 4, Issues 1-6
1968
Pg. 60:
It says: “You can’t ride two horses with one arse!”
     
July 1973, The Accounting Review (Menasha, WI), “Book Reviews” by Earl A. Spiller, Jr., pp. 631-632:
ABRAHAM J. BRILOFF, Unaccountable Accounting (New York: Harper & Row, 1972, pp. xvii, 365, $9.50).
(...)
I need do no more than report the title of one of the chapters—“On Riding Two Horses with One Backside.”
HERBERT E. MILLER
Partner
Arthur Anderson & Co. (Chicago)
 
8 November 1974, New Statesman (London, UK), “Television” by Dennis Potter, pg. 671, col. 1:
‘The trouble is, you’re trying to ride two horses with one arse,’ said a wasteland orator in Leeds—United! ....
   
3 December 1975, Los Angeles (CA) Times, “TV Movie Review: Adventures of a Gotham Gypsy” by Kevin Thomas, pt. 4, pg. 30, col. 1:
His people are forever coming up with such gems of Gypsy wisdom as “A man cannot ride two horses with one seat,” but (Ron—ed.) Leibman asks himself, “Who says you can’t straddle the pointed fence?”
 
Google Books
A Tale Told by an Idiot
By R. P. Noronha
New Delhi, India: Vikas Publishing House
1976
Pg. 3:
An era of ambivalence was ushered in, of riding two horses with one bottom, of lip service in private to the ideals of the Congress, and contributions to the Viceroy’s War Purposes Fund in public.
   
28 October 1978, Vancouver (BS) Sun, “A quiet climb to the top: The Joe Segal story” by Harvey Southam, C6, col. 4:
And don’t be lulled by his Will Rogers-like philosophy (“You can’t ride two horses with one ass,” he says of part-time politicians)
 
IMDb (The Internet Movie Database)
Broadway Danny Rose (1984)
Quotes
Danny Rose: My Aunt Rose, take my Aunt Rose. Not a beautiful woman at all. She looked like something you’d buy in a live bait store. But, why? She had wisdom. And she used to say, “You can’t ride two horses with one behind.” So, you see what I’m sayin’? You see, that’s my point.
     
Google Books
Big Little Book of Jewish Wit & Wisdom
By Sally Ann Berk
New York, NY: Black Dog & Leventahl Publishers
2000
Pg. 13:
You can’t ride two horses with one behind.
 
Google Books
Where There’s Smoke, There’s Salmon:
The Book of Jewish Proverbs
By Michael Graubart Levin
New York, NY: Kensington Publishing Corporation
2001
Pg. 144:
You can’t ride two horses with one tuchas.
YIDDISH PROVERB
         
IMDb (The Internet Movie Database)
Sweet Home Alabama (2002)
Quotes
Earl Smooter: You can’t ride two horses with one ass, sugarbean.
 
Google Books
You Cant Ride Two Horses With One Ass: And Other Ways of Thinking That Will Help You Protect Your Brand
Kurt Bartolich
CreateSpace Independent Publishing Platform, Dec 17, 2015 - 128 pages
0 Reviews
What is the biggest threat to your business today? It’s not disruption, competition or the economy. The enemy is between your ears. Innovation, scaling, partnerships, etc., can sabotage your brand’s authenticity. Even your company mission can undermine it. You Can’t Ride Two Horses With One Ass flips conventional thinking on its ear to teach you a new ethos: How to grow your business by protecting your brand’s authenticity.
 
Twitter
Fred From Plano
@FredFromPlano
“You can’t ride two horses with one rear end. You know what I’m saying?” SEC Network’s Andy Kennedy is shaking up the basketball and the equestrian world simultaneously with his pithy sayings! #SECTournament #DixieStampede
8:41 PM - 13 Mar 2019