Hours after former CNN host Piers Morgan was told to "fuck off" by a comedian after he said President Trump's travel ban is not a "Muslim ban," the former CNN host found himself in a Twitter fight with Harry Potter author J.K. Rowling.

During a Friday evening panel on Bill Maher's "Real Time" show on HBO, Morgan disputed the host's assertion that Trump instituted a Muslim ban when he signed an executive order barring citizens from seven Muslim-majority nations with high terror risk.

Morgan and Trump have history, as Morgan was the victor on Trump's "Celebrity Apprentice" in 2008, and is a self-described friend of the president's.

His comment earned a swift rebuke from comedian and fellow panelist Jim Jefferies who said, "fuck off," before comparing Trump's fledgling presidency to Adolf Hitler's Nazi Germany.

Morgan fired back, calling comments like that, "hysterical, over-the-top nonsense."

Early Saturday morning, Rowling, a vocal Trump critic, applauded Jeffries' statement.

"Yes, watching Piers Morgan being told to fuck off on live TV is *exactly* as satisfying as I'd always imagined," Rowlingn tweeted.

Morgan tweeted back at Rowling: "This is why I've never read a single word of Harry Potter."

Their spat on social media continued back-and-forth, with Morgan defending his comments as "factual" and Rowling criticizing Morgan for not reading the Harry Potter books because he would have learned "the downside of sucking up to the biggest bully in school is getting burned alive."