This statement derives from the general relativity theory published by Albert Einstein in 1915. It refers about the event in which an accelerated body crosses the spacetime boundary of a black hole known as the "event horizon". Beyond this boundary or "point of no return" the gravitational pull becomes so great as to make escape impossible and thus "you'll never go back".
"If a black hole is an oyster then the singularity is the pearl inside. The gravity is so strong it’s always hidden in darkness, beyond the horizon. That’s why we call it a black hole, once you go black you'll never go back."
by byfron March 15, 2018
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If you start listening to black metal you can never again stomach normal metal bands like Slipknot and Metallica. The force of darkness is too powerful
Joey didn’t go to the Metallica concert on Saturday because he only listens to Burzum and Mayhem. “Once you go black you’ll never go back” , he said forcefully, before returning to carving a pentagram.
by Harambe 2020 January 5, 2020
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This means once you date a black man or women you never go back to dating other races.
Rebecca: I never knew betty was into black guys like that
Sam: After that one night stand with the black guy across the street shes never been the same
Rebecca: What happened?
Sam: She dates black guys only
Rebecca:Damnn
Sam: once you go black you never go back
by Aaaa214 November 20, 2019
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Just like 1 being larger than 2, "once you go black you'll never go back" is false.
by Vergilkilla August 17, 2007
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Vulgar idiom with American origin is typically used to imply that sexual activity with an African American or a black person is so enjoyable that one will exclusively seek out black partners in the future because of that.

Likely to harken back from taboos surrounding African Americans during the Antebellum period in United States history. During this period, large amounts of stereotypes existed around African Americans, many, also sexual. Racist ideas were held like that black men were considered to be animalistic and unable to control their sexual urges, which made having a romantic relationship with a black man, especially as a white woman, extremely taboo. All southern states had anti-miscegenation (anti-interracial marriage) laws, which weren’t abolished until June 12, 1967, by Federal law.

Many kinks surrounding black men specifically, like many kinks, are rooted in older taboos, which are now gone.
Ava said that since her last boyfriend, she has had an amazing sex life.”
“Well you know what they say.”
“Yeah, 'Once you go black, you never go back'.”
by CapeCodSpruce June 5, 2021
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Once a woman sleeps with a black man, no white man will be able to satisfy her, so she sleeps only with black men from then on. Usually because of their girth and size, but also because they appreciate more types of women in general and have better moves.
After she'd been with two black guys, she realized that once you go black, you never go back, because size really does matter.
by ksbunny July 27, 2012
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Basically saying that once a woman dates and has sex to a black man, the size of his penis will make her never go back to white men.
Girl 1: I love my black boyfriend, we are gonna have sex.

Girl 2: But "once you go black, your never going back!"
by secret12345678910 March 3, 2011
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