The word “apparent” sounds like “a parent.” A dad joke was posted on Twitter on December 9, 2014:
 
Q: When does a joke become a dad joke?
A: When the punchline becomes apparent.
 
The classic dad joke has been printed on many images and has been popular on Father’s Day. “When does a joke become a dad joke? When the punchline becomes apparent. When does the punchline become apparent? After the delivery” was posted on Twitter on February 15, 2018.
     
Different punchlines include “When does a joke become a dad joke?”/“When it leaves you and never comes back” and “When does a joke become a dad joke?”/“When it’s fully groan.”
         
     
Twitter   
🤙🏼 luke 🤙🏼‏
@llukehudsonn
When does a joke become a dad joke?
When the punchline becomes apparent HARHARHAR
7:34 AM - 9 Dec 2014
   
Twitter
new year, new meme‏
@Rugbysmartarse
Replying to @GoodDay_ToYou
@GoodDay_ToYou @RavenZech @mistermouse666 when does a joke become a dad joke? When the punch line becomes apparent…...
12:37 AM - 10 Dec 2014
 
Twitter
byck‏
@fairtirade
Replying to @p_perez
@p_perez @JB_AU When is a joke a dad joke? When the punchline becomes apparent.
12:20 AM - 4 Feb 2015
   
Twitter
Kasara Bangbang‏
@MissKasara
How do you know when a joke is a “dad joke?” ... It becomes apparent.
2:50 AM - 26 Feb 2015
 
Twitter
Australia‏
@WeAreAustralia
Q. When does a joke become a dad joke?
.
A. When the punchline becomes apparent
5:08 AM - 17 Nov 2015
 
Reddit—Jokes
When does a joke become a dad joke?
submitted March 26, 2016 by belungawhale
When the punchline becomes apparent.
COMMENTS
PassmasterFlash
When it becomes a groan-up.
 
everred
“Fully groan” also works
     
Reddit—Jokes
When does a joke become a dad joke?
submitted August 29, 2016 by ThePublicCats
After the delivery
(Pls….just let me go and don’t hurt my family)
 
Twitter
NPR‏
@NPR
When does a Dad joke become a Dad joke?
When it becomes apparent.
9:30 AM - 18 Jun 2017
 
Reddit—Jokes
When does a dad joke become a dad joke?
submitted June 18, 2017 by lucidlogik
When it becomes apparent.
COMMENTS
skrub55
For the less punny people: apparent contains the word parent.
     
Reddit—Dad Jokes
When does a joke become a dad joke? (self.dadjokes)
submitted September 25, 2017 by chipppofftheolblock
When the joke becomes apparent
COMMENTS
tinabelchersbutt
When it’s fully groan!
 
cerebral23
When it’s recycled almost daily in /r/dadjokes !
 
Reddit—Dad Jokes
When does a regular joke become a dad joke? (self.dadjokes)
submitted October 2, 2017 by ArtfulDues
When it becomes apparent.
 
Twitter
LaffGaff‏
@LaffGaff
When does a joke become a dad joke?
When the punchline becomes apparent.
When does the punchline become apparent?
After the delivery.
#funny #jokes #jokeoftheday
4:12 PM - 15 Feb 2018