Poppy Harlow leaves CNN set after tense exchange with Don Lemon

Don Lemon’s acidic behavior has turned the stomach of another co-anchor.

A furious Poppy Harlow walked off the “CNN This Morning” set Thursday following a tense exchange with Lemon after he said GOP presidential candidate Nikki Haley was “not in her prime,” The Post has learned.

According to sources with knowledge of the situation, Harlow took a “well-timed” bathroom break and was followed into the restroom by co-host Kaitlan Collins — who recently had her own run-in with Lemon.

The tense relationship between Lemon, Collins and Harlow has “been smoldering for months,” the source said.

However, CNN boss Chris Licht seems content to keep rolling out the troubled trio.

“Licht isn’t doing anything about it,” the source said.

During an informal meeting Thursday, dubbed “Coffee with Chris,” 30 staffers peppered Licht with questions about the ratings-challenged network.

One asked about Lemon’s comments about the 51-year-old Haley, according to a source with knowledge.

“People say stupid things and that if it’s a trend then there’s recourse,” the source said, paraphrasing Licht’s comments.

CNN did not immediately respond to requests for comment. Lemon didn’t respond to a request for comment.

Harlow did not comment. But a source close to the veteran anchor quipped: “As a woman in her prime, Poppy Harlow does use the bathroom, including on Thursday mornings.”

Collins did not return requests for comment.

Harlow, 40, came back to finish Thursday’s program but had looked stunned on the air when Lemon went on his head-scratching diatribe over Haley calling for mental competency tests for politicians over the age of 75.

“This whole talk about age makes me uncomfortable,” the 56-year-old Lemon began. “I think it’s the wrong road to go down. She says people, you know, politicians are suddenly not in their prime. Nikki Haley isn’t in her prime.”

To the bewilderment of Harlow and Collins, Lemon then said: “A woman is considered to be in their prime in [their] 20s and 30s and maybe 40s.”

Harlow immediately called out the failed primetime host: “What are you talking about, wait … Prime for what?”

Lemon quickly tried to save himself by claiming he wasn’t stating his personal beliefs.

“That’s not according to me,” he said. “It’s like, prime. If you look it up. If you Google when is a woman in her prime, it’ll say 20s, 30s and 40s.”

He continued: “I’m just saying Nikki Haley should be careful about saying that politicians are not in their prime and they need to be in their prime when they serve. Because she wouldn’t be in her prime according to, you know, Google.”

After receiving widespread backlash internally and via Twitter, Lemon issued a public apology.

“The reference I made to a woman’s ‘prime’ this morning was inartful and irrelevant, as colleagues and loved ones have pointed out, and I regret it,” Lemon tweeted. “A woman’s age doesn’t define her either personally or professionally. I have countless women in my life who prove that every day.”

“This ongoing situation is frustrating,” a source with knowledge said, referring to Lemon’s attitude on set. “His comments were misogynistic and sexist.”

In December, Lemon had screamed at Collins after she interrupted him on the air. The two have rarely appeared on set since, though the 30-year-old Collins was there Thursday.

A CNN producer had asked Lemon to take a day off after he reamed out Collins in December for interrupting him during a broadcast, a source told The Post at the time.