The “Smile” singer revealed in her shocking new autobiography that she once made out with Zoe Kravitz while still married to Sam Cooper.
Allen, 33, admitted the make-out session with 29-year-old Kravitz occurred during her 2014 tour.
“For my New York shows, Zoe Kravitz and her band Lolawolf supported me, so I got to know Zoe a bit,” wrote Allen in her book, My Thoughts Exactly. “We became friends.”
“Later in the tour, when we were in Washington, the girls and their nanny, Jess, came out to visit me for a few days, but I had to go back to New York for a day or so for work,” she continued.
However, the kiss with Kravitz wasn’t Allen’s only fling with a fellow singer.
Allen also admitted to hooking up with ex-Oasis frontman Liam Gallagher, 45, after they got “hammered” together and joined the mile-high club while they flew together to Japan for the Fuji Rock Festival in 2009.
After they got drunk, she wrote, “at some point Liam and I found ourselves together in the toilet doing something that he shouldn’t have been doing, and it wasn’t drugs. Then we were in a lie-down bed together.”
“Zoe and I went out partying and ended up kissing. I heard that later that same night she’d got down with A$AP Rocky.”
“When we landed in Tokyo, Liam said, in his distinctive nasal twang, ‘What you doing now? Why don’t you come back to our hotel’… I was like, ‘Yeah, OK,’” she continued.
According to Allen, Gallagher, who was married to All Saints singer Nicole Appleton at the time, begged her to never reveal their fling to anyone.
“It wasn’t until the next day when he said something like, ‘No one can hear about this because of Nic’, then I clocked he was married,” she recalled.
Allen, who’s a mother of two, recently revealed on Instagram she even had intimate relations with female sex workers after she suffered post-natal depression amid her crumbling relationship with Cooper.
LONDON, ENGLAND - SEPTEMBER 17: Lily Allen attends attends the LOVE Magazine 10th birthday party with Perrier-Jouet at Loulou's on September 17, 2018 in London, England. (Photo by David M. Benett/Dave Benett/Getty Images for LOVE Magazine/Conde Nast)
LONDON, ENGLAND - SEPTEMBER 17: Lily Allen seen attending LOVE Magazine party at No 5 Hertford Street (Loulou's) during London Fashion Week September 2018 on September 17, 2018 in London, England. (Photo by Ricky Vigil M/GC Images)
LONDON, ENGLAND - SEPTEMBER 16: Lily Allen attends the Fashion East front row during London Fashion Week September 2018 at the My Beautiful City Show Space on September 16, 2018 in London, England. (Photo by David M. Benett/Dave Benett/Getty Images)
PARIS, FRANCE - JULY 03: Lily Allen attends the Chanel Haute Couture Fall Winter 2018/2019 show as part of Paris Fashion Week on July 3, 2018 in Paris, France. (Photo by Pascal Le Segretain/Getty Images)
British singer Lily Allen attends the Dior Men's Spring/Summer 2019 fashion show on June 23, 2018 in Paris. (Photo by FRANCOIS GUILLOT / AFP) (Photo credit should read FRANCOIS GUILLOT/AFP/Getty Images)
PARIS, FRANCE - JUNE 23: Virgil Abloh and Lily Allen attend the Dior Homme Menswear Spring/Summer 2019 show as part of Paris Fashion Week Week on June 23, 2018 in Paris, France. (Photo by Stephane Cardinale - Corbis/Corbis via Getty Images)
LONDON, ENGLAND - JUNE 03: (EDITORIAL USE ONLY) Lily Allen performs on stage at Mighty Hoopla festival at Brockwell Park on June 3, 2018 in London, England. (Photo by Joseph Okpako/WireImage)
LONDON, ENGLAND - MAY 17: Lily Allen leaving the Planet Aries store in Covent Garden on May 17, 2018 in London, England. (Photo by Mark R. Milan/GC Images)
LOS ANGELES, CA - APRIL 25: Lily Allen performs at El Rey Theatre on April 25, 2018 in Los Angeles, California. (Photo by Tibrina Hobson/Getty Images for WBR)
LATE NIGHT WITH SETH MEYERS -- Episode 674 -- Pictured: Musical guest Lily Allen performs on April 23, 2018 -- (Photo by: Lloyd Bishop/NBC/NBCU Photo Bank via Getty Images)
PARIS, FRANCE - APRIL 09: Lily Allen performs at Le Badaboum on April 9, 2018 in Paris, France. (Photo by David Wolff - Patrick/Redferns)
PARIS, FRANCE - APRIL 09: Singer Lily Allen is seen at Orly airport on April 9, 2018 in Paris, France. (Photo by Marc Piasecki/GC Images)
BERLIN, GERMANY - APRIL 06: British singer Lily Allen performs live on stage during a concert at the Lido on April 6, 2018 in Berlin, Germany. (Photo by Frank Hoensch/Redferns)
PARIS, FRANCE - JUNE 22: Lily Allen is seen arriving at Louis Vuitton fashion show during Paris Fashion Week - Menswear Spring/Summer 2018 on June 22, 2017 in Paris, France. (Photo by Jacopo Raule/GC Images)
PARIS, FRANCE - MARCH 07: Lily Allen attends the Chanel show during Paris Fashion Week Womenswear Fall/Winter 2017/2018 on March 7, 2017 in Paris, France. (Photo by Danny Martindale/GC Images)