The acerbic American Idol judge got the surprise of his career during the show's Q&A session Wednesday, when a British woman – identified only as Tara, 46, from Petaluma, Calif. – called in and announced to the nationwide audience that she had been Cowell's first kiss.
Uncharacteristically flustered, Cowell quickly recognized the voice – asking if she was really Tara Miller, whom he smooched at age 9.
It was, indeed. And, later that night, she chatted with PEOPLE about the fateful pucker.
"He'd taken me to the bottom of his garden," said Tara, whose last name is now McDonald-Smith. "It was very cute and it was very memorable. We were just kids. We didn't know what we were doing!"
Kiss and TellAs for who made the first move, Cowell's former neighbor in Radlett, Hertfordshire swears she can't remember.
"Really, I can't," McDonald-Smith insisted. "In those days there was like three channels on the television, there were no computers. We used to play spin the bottle ... and I got him a lot of the time. It was all good."
So what prompted her to reach out after all these years? "I saw him on American Idol and [I thought] wow, that's amazing," she explained. "It was just one of those This is Your Life-type situations, and I thought I'd go for it. I hope I didn't embarrass him."
And, for the record, McDonald-Smith is not at all surprised that her childhood pal turned out to be TV's favorite Mr. Nasty.
Even back then "he was pretty forthcoming and said what he thought," recalled the single mom, who has three sons Connor, 17, Rory, 16, and Liam, 11. "He was not too different than he is today."
Now that they've reconnected, the North California-based sales manager would welcome an in-person reunion.
"I'd love to meet up with him. I seriously would," she said. "We were good friends... and I think it would be great fun."
Reporting by ANN COCCAGNIA