Cher is recounting the time she was left feeling "mortified" after performing for a member of the royal family.

In her new "brutally honest" book Cher: The Memoir, the pop icon detailed the time she and Sonny Bono performed for Princess Margaret, the younger sister of Queen Elizabeth, when she was in Los Angeles and how the entire thing was a "fiasco," per People.

"Having read all about us in the English press, the princess invited us to perform at the Hollywood Palladium," she said, adding, "This came as a surprise, because the old guard either had no idea who we were or thought we were freaks. It boggled the imagination how much that wasn't our audience. The best that could happen is we'd live through it."

Despite neither party wanting to go through with their Sonny & Cher performance, they came to the conclusion that they "couldn't say no to Princess Margaret." However, the "Believe" singer said "the whole event was a fiasco."

"The acoustics were so bad that, coupled with the sound problems, we performed terribly," she wrote.

Cher even referenced a negative review from a critic that said they "howled like a pair of coyotes," noting that the crowd would likely agree with that description.

"The audience must have agreed, because very few people applauded, and halfway through our set Princess Margaret asked for the sound to be turned down because she had a headache," Cher recalled. "The engineer then accidentally cut the mic and interfered with what we could hear, which threw Sonny completely."

Cher admitted she was "mortified" with the entire ordeal, writing, "It was like a bad dream that we couldn't get out of; we just had to stand there and wait for it to be over."

Elsewhere in her memoir, Cher revealed new details about her marriage to Bono, including how she felt "trapped" in a "loveless" relationship.

LISTEN: