Larry King was blindsided by the revelation of his wife’s alleged affair, Page Six is told.

Insiders say that he believed Shawn King, his wife of 19 years, was faithful to him and only learned abouther year-long romance with an as-yet-unidentified man when the National Enquirer contacted his representatives for comment.

Shockingly, an insider says that Shawn met the man when he was a guest on the podcast she makes with her husband, “Back and Forth with Shawn and Larry.”

“He’s heartbroken,” a friend of Larry’s told us. “He’s embarrassed and furious.”

The source said that although Shawn — who the Enquirer reported on Wednesday had sent nude pictures and had “steamy afternoon sex sessions” with her boy toy — is still living with Larry after the news hit, the 82-year-old veteran broadcaster hasn’t made a decision on whether to file for divorce.

“All options are being considered,” said the pal. “Nothing has been ruled out.”

In fact, the insider says that before the scandal broke, Shawn “was ready to divorce Larry for this guy, but the guy was hesitant about it.”

The insider revealed that Shawn and Larry’s marriage has effectively been over since around 2010 and that the couple sleep in separate rooms in their Beverly Hills home.

“They just show up for appearances. She loves being Mrs. Larry King and the travel,” said the source. “She stays with him for the kids’ sake.” The couple has two teenage sons.

The friend said Shawn and Larry have a testy relationship. “He’s 82 years old, he’s survived cancer twice, heart surgery and he’s diabetic,” they said. “When this came out last week, some of us were actually happy, hoping this will finally mean that he can live his life in some sort of peace, should they decide to divorce.”

Lawyers for Larry and Shawn have called the Enquirer story “inaccurate.”

This article originally appeared in the New York Post's Page Six.