Lily Allen has admitted she once walked in on James Blunt getting rather up, close and personal with someone.

Allen, 33, made the confession during an interview with Yahoo’s Be, saying the incident took place while the pair were staying at Hollywood’s Chateau Marmont.

As she was asked about any shameless things she’d witnessed, the “Smile” hitmaker said, “I once walked in on somebody having sex with James Blunt in the foyer of my hotel room at Chateau Marmont.

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“Not that it’s shameful to have sex with James Blunt. It was just that it happened to be happening in the foyer of my hotel room.”

The musician’s latest admission comes after she revealed she previously slept with female escorts.

Allen, who is set to release her memoir “My Thoughts Exactly” on September 20, gave fans a heads-up on Instagram that the Mail on Sunday was about to leak some details from the upcoming book.