Don Lemon returned to his CNN morning gig Wednesday and, if you tuned in to see some fireworks on set or an apology from the anchor, you were very disappointed.

Instead, Lemon tweeted an apology about 30 minutes before appearing on CNN This Morning, nearly a week after he made sexist on-air remarks.

Lemon tweeted, "I appreciate the opportunity to be back on @CNNThisMorning today. To my network, my colleagues and our incredible audience — I’m sorry. “I’ve heard you, I’m learning from you, and I’m committed to doing better. See you soon."

Then Lemon opened the show with a rather dull segment alongside cohost Poppy Harlow in the studio while Kaitlan Collins was reporting from Warsaw, Poland, where she's covering President Biden.

Don commented on Biden's speech about Kyiv standing strong one year after Ukraine was invaded by Russia. He turned to Harlow and said, "Very powerful speech from the President."

Harlow responded, "Very powerful and juxtaposed to what we heard from Putin in the morning," referring to the Russian President's speech in opposition to Biden's.

Harlow then turned to Lemon and cheerfully added, "What a day. Good morning everyone, Don and I are here in New York. And Kaitlin is live again in Warsaw Poland."

There was no mention of Don's sexist on-air remarks from last week -- nor was there an on-air apology from Lemon. It seemed like they were playing the role of a happy family on set or, at least, that's how the hosts were trying to portray it.

But, behind the scenes, there's much tension. As we reported ... Don is one strike away from being canned by the network. Our sources say if he screws up again, he's out!

We're told senior CNN executives gave the final warning to Don when they spoke to him this week. Don might not be so sad if he leaves. We're told he's not happy at CNN anyway.

And last week's debacle only ratcheted up the tensions. As you know, Lemon made sexist comments on air about 2024 Republican presidential candidate Nikki Haley calling her past her prime at 51.

His cohosts, Harlow and Collins, were shocked and offended as were most of the CNN staff. Don tried to apologize, but his coworkers gave him the cold shoulder.