When Piers Morgan Tonight aired at 9 p.m. EST on CNN September 19, the evening's previously scheduled guest, Kelsey Grammer, was M.I.A.

According to British TV journalist Piers Morgan, 47, the Boss actor, 57, "saw a photo of his ex-wife Camille in the open to our show and legged it. Extraordinary. Never had this happen before. . .I had a very friendly chat with Kelsey backstage, He said he was really looking forward to the interview. Weird."

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According a CNN source, Grammer's exit was especially surprising given his candid August 26 interview on Oprah's Next Chapter, where he talked about his former marriages, career woes and family tragedies. "No one on Kelsey Grammer's team said anything about not mentioning Camille beforehand," the CNN source tells Us Weekly. "He was just talking about her last week."

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Morgan later made a few jokes about the incident via Twitter with fellow Brit Simon Cowell, 52, telling the music mogul, "I suspect Kelsey was watching X Factor in the green room and suddenly felt nauseous."

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All kidding aside, Morgan said that while he likes Grammer as a person, "This was a shockingly unprofessional thing to do. I wasn't even going to mention his ex-wife!"

Morgan, who also interviewed Pulitzer Prize-winning journalist Nicholas Kristof for the September 19 broadcast, will appear on NBC's Late Night with Jimmy Fallon September 20.

"Relax, Jimmy," Morgan tweeted. "Unlike my guest Mr. Grammer last night, I won't run away."

This article originally appeared on Usmagazine.com: Kelsey Grammer Abruptly Cancels Piers Morgan Interview Over Ex-Wife Camille