A popular supermarket barcode joke is:
 
“So I was in Tesco’s and I saw this man and woman wrapped in a barcode. I said, ‘Are you two an item?’”
 
Tesco is a supermarket chain in the United Kingdom. The joke has been credited to both British prop comedian Tommy Cooper (1921-1984) and British comedian and actor Peter Kay (born 1973). The supermarket joke has been cited in print since at least 2001 and has been printed on many images.
     
       
Wikipedia: Tommy Cooper
Thomas Frederick Cooper (19 March 1921 – 15 April 1984) was a British prop comedian and magician. Cooper was a member of the Magic Circle, and respected by traditional magicians. He was famed for his red fez, and his appearance was large and lumbering, at 6 feet 4 inches (1.93 m) and more than 15 stone (210 lb; 95 kg) in weight. On 15 April 1984, Cooper collapsed, and died soon afterwards, from a heart attack on live national television.
 
Wikipedia: Peter Kay
Peter John Kay Hon. D.A. (born 2 July 1973) is an English comedian and actor. His 2010-11 stand-up comedy tour was officially inaugurated into the Guinness World Records as the most successful of all time,  playing to over 1.2 million people.
 
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Puns - enjoy….
crazyjeyesy
1/25/01
(...)
So I was in a supermarket and I saw a man and a woman wrapped in a barcode. I said, “Are you an item?”
   
Google Groups: uk.local.southwest
Jokelets
The Skipper
11/19/01
(...)
...So I was in Tesco’s and I saw this man and woman wrapped in a barcode. I said “Are you two an item?”.
 
Google Groups: uk.local.cumbria
Peter Kay Classics
Lou Smorals
6/11/03
(...)
So I was in Tesco’s and I saw this man and woman wrapped in a barcode. I said “Are you two an item?”.
   
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OT Tommy Cooper.. The lighter side of life
Me
4/7/04
(...)
I was in Tesco’s and I saw this man and woman wrapped in a barcode. I said “Are you two an item?”.
 
Twitter
MoCoDo
‏@MoCoDo
Just been to Tesco’s and I saw this man and woman wrapped in a barcode. I said ‘Are you two an item?’
11:50 AM - 5 Mar 2009
 
Twitter
Trevor Ship
‏@trevypoos
when I was shopping I saw two people wrapped in a barcode. I assume that they were an item.
1:16 PM - 25 Mar 2009
 
Google Books
The Biggest Ever Tim Vine Joke Book
By Tim Vine
London: Century
2010
Pg. 177:
So l was in Tescos and I saw this man and woman wrapped in a bar code. I said are you two an item?
 
Google Books
Ultimate Book of Jokes:
The Essential Collection of More Than 1,500 Jokes
By Scott McNeely
San Francisco, CA: Chronicle Books
2011
Pg. 338:
I walked into a supermarket and saw a man and a woman wrapped in a barcode. I said, “Are you two an item?”
 
Google Books
A Freudian Slip Is When You Say One Thing but Mean Your Mother:
879 Funny, Funky, Hip, and Hilarious Puns
By Gary Blake
New York, NY: Skyhorse Publishing
2012
Pg. ?:
When I was in the supermarket, I saw a man and a woman wrapped in a barcode. I asked: “Are you two an item?”
 
Google Books
5,000 Great One Liners
Compiled by Grant Tucker
London: Biteback Publishing
2012
Pg. ?:
When I was in a supermarket I saw a man and a woman wrapped in a barcode. I asked, ‘Are you two an item?’
 
Facebook
Top 50 funniest jokes ever told
January 5, 2013 at 2:52pm
(...)
Comedy genius Tommy Cooper had by far the most jokes in the list, which also includes gags by Peter Kay and Lee Evans.
(...)
29.  I was in Tesco’s and I saw this man and woman wrapped in a barcode. I said, ‘‘Are you two an item?’‘
 
Twitter
LaffGaff
‏@LaffGaff
I was at the supermarket the other day when I saw a man and woman wrapped in a barcode. I said, “Are you two an item?” #funny #jokes
4:12 PM - 29 Apr 2015