The man who damaged David Bowie’s eye during a teenage disagreement said he still worries about the moment to this day.

George Underwood met David Jones – later Bowie – when the pair were 9 years old. Long after settling their dispute over a potential girlfriend, they traveled the world together, and Bowie made frequent use of Underwood’s artistic abilities, as he designed the covers of Hunky Dory and Ziggy Stardust.

Marking the launch of an exhibition in London, Underwood told the BBC that the argument had been over a girl named Carol.

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“We were always together – we were very good friends and we used to go up and down Bromley High Street all dressed to the nines, thinking we were God’s gift, trying to chat up all the girls,” he recalled.

Both boys had attempted to attract Carol at a 15th birthday party, and she’d agreed to meet Underwood later at the local youth club – but then Bowie told him she’d changed her mind and was going to meet him instead.

“I decided to go down the youth club anyway a little bit later on, because I’d never been there before,” Underwood continued, “and her mate came out shouting: ‘Where have you been? Carol’s been waiting for you for over an hour!’ I thought, ‘Uh-oh. David’s told me a porky-pie [lie] here.’”

A friend urged Underwood to “stick one on” Bowie, and that’s what he did.

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The rock star later explained: “It wasn’t a very hard punch but obviously caught me at a rather odd angle,” admitting that he’d been “boasting to my mate about what a Casanova I was.”

The result was that Bowie’s left iris became paralyzed, giving the impression that the eye was a different color than his right, and magnifying the red-eye effect of flash photography.

“It was just horrible,” Underwood said. “I didn’t like it at the time. But of course later on, lo and behold, he says I did him a favor because it’s given him this enigmatic, otherworldly look.”

Teenage spat aside, Underwood remembered his friend fondly. “I miss him deeply because he went too soon, as we know, and he was just great to be with, always fun to be with. We laughed a lot,” he said. “I often wondered whether every time he looked in the mirror he thought of me.”

Underwood went on to design album covers for artists such as T. Rex, Procol Harum and Mott the Hoople as well as Bowie, yet he confessed the eye incident still haunts him: “I’m just a bit worried that I might have it carved on my tombstone.”