Don Lemon gave his “CNN This Morning” co-host Kaitlan Collins an “air kiss” during an awkward celebration of her birthday — just weeks after he reportedly berated her in front of colleagues for allegedly interrupting him on the air.

“We know you hate this,” Lemon said as he approached Collins on-set during Friday’s broadcast, giving her a half embrace and air kiss somewhere behind the top of her head.

Collins responded with a tight smile and turned her head to the side as Lemon broke out into “Happy Birthday to You” and handed Collins a bouquet of flowers and a present inside a bag decorated with a smiley face and a balloon.

“Do not open this because it’s something that you told me that you wanted but you cannot open it,” Lemon told Collins.

Co-host Poppy Harlow then walked over to Collins and gave her a warm embrace which — unlike with Lemon — Collins returned, putting her arm around Harlow’s neck and appearing to relax a bit.

Lemon then told Collins that his partner, Tim Malone, bought the gift on Thursday while he was at the barbershop. Lemon added that he tried and failed to find a jersey for the University of Alabama football team, which he had hoped to wear under his suit on Friday.

“We could not find it in Manhattan yesterday,” Lemon said. “I was in the barbershop and Tim was, like, walking all around Manhattan trying to find it. We never found it.”

“That would have been something,” Collins, an alum of the Tuscaloosa-based university and a devoted fan of the Crimson Tide, told Lemon. “You guys are the best. Thank you very much.”

A blushing Collins then told her co-hosts and the CNN crew: “Thank you for not doing anything else because I would have hated it.”

“Kaitlan put the kibosh on the rest of this celebration,” Harlow said, saying it was going to start at 9 a.m. telling viewers to look at Collins’ Instagram for updates.

“Why are you scared?” Lemon could be heard asking Collins as the camera panned back for the end of the broadcast.

As of 10:45 a.m., there were no updates on Collins’ Instagram.

Lemon’s chivalrous gesture came on the heels of a damning Variety exposé detailing alleged instances of misogynist behavior that was directed toward a number female colleagues at the all-news cable outfit.

As reported by The Post, Collins was left visibly upset and darted out of the studio after Lemon chewed her out at the conclusion of the Dec. 8 broadcast of their morning show, according to sources with knowledge of the situation.

Lemon’s tongue-lashing of Collins did not sit well with CNN boss Chris Licht, who is said to have been appalled by Lemon’s behavior.

Last month, The Post was the first to report that Collins parted ways with Jay Sures, the superagent at United Talent Agency who also happens to represent Lemon.

Collins’ future at the morning show is reportedly murky as Licht wants to see how the former White House correspondent would fare in primetime.

According to Puck, Licht is preparing Collins for a “trial run” in the 9 p.m. hour next week.

CNN has had difficulty finding a full-time replacement for long-departed primetime star Chris Cuomo.

Licht has tried out Jake Tapper in the 9 p.m. slot with little success.

The CNN executive is reportedly training his sights on a big-name acquisition, with basketball loudmouth Charles Barkley and CBS morning star Gayle King being mentioned as candidates.

Lemon was the longtime host of his own 10 p.m. show until Licht’s arrival.

The new management at CNN moved Lemon to the mornings in what was widely viewed as a demotion.

In February, Lemon got into an on-air argument with his other co-host, Poppy Harlow, who took umbrage at his contention that Nikki Haley, the 51-year-old Republican presidential candidate, was “not in her prime.”

The remark sparked widespread backlash, forcing Lemon to apologize.

After a three-day hiatus, CNN then required Lemon to undergo sensitivity training before being allowed back on the air.

Another awkward on-air exchange took place when Lemon said that the US men’s national soccer team should get paid more than the women’s team because the men were “more interesting to watch.”

Lemon is reportedly weighing a possible lawsuit against Variety after it reported a pattern of “diva-like behavior” during his nearly two-decade stint at CNN.

According to Variety, Lemon sent threatening text messages from an anonymous number to co-anchor Kyra Phillips because he was upset that she was given the plum assignment of covering the aftermath of the American invasion of Iraq.

A spokesperson for Lemon contended that he never sent the text.

Lemon is also alleged to have once remarked to other staffers that he did not consider Soledad O’Brien authentically black, according to Variety.

A CNN spokesperson told The Post, “Don denies making any related remark in a derogatory way.”

Lemon, who is African American, was said to have been smarting from CNN’s decision to name O’Brien, whose father was white and whose mother was Afro-Cuban, as the host of a docuseries about black people.