CNN's Don Lemon Slams Prince Harry for        Detailing Argumen With Prince William

CNN's Don Lemon said Prince Harry's decision to detail an alleged physical altercation with Prince William was "gauche." See what other stars are saying about Harry's upcoming memoir, Spare.

Watch: Prince Harry Alleges Prince William "Knocked" Him to the Ground

What happens in the family, stays in the family—at least Don Lemon thinks so.

The CNN This Morning anchor gave his two cents on Prince Harry's allegation—which he details in his upcoming memoir, Spare—that Prince William engaged in a physical altercation with him, calling it "gauche" to make the accusation public.

"Everyone has a family," Don said Jan. 5. "I have arguments in my family. Am I going to put that out there for the whole world to see? I just don't understand why on earth he would want to put that out there. I know he's selling a book, but, to me, it's just not done."

"What could be achieved?" Don asked. "What exactly is he achieving by airing family dirty laundry? That's the question."

In Spare, Harry recalled the moment where tensions with William reached a fever pitch over his relationship with Meghan Markle, according to the Spanish language version of his book, obtained by NBC News.