Aaron Carter claimed he took Hilary Duff’s virginity on what he believed to be her 13th birthday, according to a new memoir that will come out next week.
The late pop star — who was found dead in a bathtub at his home in California on Saturday — made the bombshell declaration in his alleged posthumous autobiography, “Aaron Carter: An Incomplete Story of an Incomplete Life,” co-written over a three- year period with author Andy Symonds.
“Hilary and I lost our virginity to each other at a hotel… in LA,” Carter wrote in the admittedly unfinished tell-all, obtained by The Post prior to its publication. “I think it was her birthday, maybe her 13th, but I don’t remember. Her friends walked in, and we just yelled at them to get out.”
Ballast Books announced Wednesday via a press release that the memoir will be published on Nov. 15: “This book is not completed, but now it never will be,” its Amazon listing reads. “In its final version as published, notes are left in the manuscript by Aaron’s writer and publisher so the reader can see the focus and direction where the book w[as] going.”
A rep for Duff did not confirm or deny Carter’s claim, telling The Post in a statement: “We would never comment on Hilary’s personal life in this way.”
The Post also reached out to Carter’s reps for comment.
Carter previously claimed that he began dating Duff on his own 13th birthday, which was Dec. 7, 2000. In his book, he said he had the pick of actresses at his 13th birthday party — and he struck up a relationship with Duff.
Duff is a couple of months older than Carter and would have already been 13 if they started dating on his 13th birthday.
The former couple famously shared an on-screen kiss on Duff’s Disney Channel series “Lizzie McGuire.” The episode aired March 23, 2001.
In an interview with Acesparks’s “The Big Idea with Donny Deutsch” a few years later, Carter purportedly stated: “I started dating Hilary on my 13th birthday. I was dating her for like a year and a half, and then I just got a little bored, so I went and started getting to know Lindsay [Lohan], dating Lindsay. Then I didn’t want to do that anymore, so I got back with Hilary.”
Carter and Duff ended their on-and-off romance around 2003.
The “Younger” actress — who is now 35 and married to Matthew Koma — has previously hinted that she lost her virginity to Good Charlotte rocker Joel Madden.
Duff dated Madden from 2004 to 2006, with their romance sparking headlines due to the eight-year age difference.
“I had a 26-year-old boyfriend,” Duff told Cosmopolitan in 2015. “So everyone can make their own assumptions about what I was doing.”
Duff paid tribute to Carter following his untimely death at the age of 34, sharing a sweet note to Instagram that read: “For Aaron — I’m deeply sorry that life was so hard for you and that you had to struggle in front of the whole world.
“You had a charm that was absolutely effervescent,” she added. “Boy, did my teenage self love you deeply.”
In Carter’s memoir — which was a rough draft at the time of his untimely death, with many unanswered questions — he recalled some of his other relationships, saying actress Amanda Bynes was his first girlfriend. He also claimed that his “Dancing with the Stars” partner, Karina Smirnoff, left her fiancé for him when they competed on Season 9.
“I let her know she was too much for me, and she agreed, and we started resenting each other in the middle of the competition, and we started having to rehearse with different people because our relationship was so bad,” Carter wrote.
The Post reached out to reps for Bynes and Smirnoff for comment. Carter made the same claim last year about Smirnoff on a podcast. In an Instagram post following his death, Smirnoff wrote, “RIP @aaroncarter So young! It’s heartbreaking! 💔💔💔 you always made people smile. Rest In Peace friend! You will be missed.”