Andy Cohen wishes he hadn't added fuel to the Princess Kate conspiracy fire.

On his SiriusXM show, the "Watch What Happens Live" host expressed regret that he joined in on conspiracy theories about the Princess of Wales now that it has been revealed that she is battling cancer. Cohen said he is "heartbroken by the news" about her health.

"Of course, I wish I had kept my mouth shut," he said. "We are all praying for Princess Kate and King Charles."

Princess Kate stepped back from the public eye after undergoing abdominal surgery in January, sparking online conspiracy theories about her health and whereabouts. In March, TMZ published a video showing the Princess of Wales and her husband, Prince William, out shopping, which would appear to put the speculation to rest. But in a post on X, formerly Twitter, Cohen wrote at the time, "That ain't Kate."

Princess Katecancer diagnosis: Read her full statement to the public

In a segment on "Watch What Happens Live," Cohen also spoke with "Last Week Tonight" host John Oliver about what was "going on" with Princess Kate after it was revealed that a photo of her with her children had been manipulated. "There is a non-zero chance she died 18 months ago," Oliver joked.

On his radio show, Cohen recalled "someone on Sky News" calling him a "numpty" over his Princess Kate coverage and said he now realizes "they were right."

Stephen Colbert, 'The View' hosts expressed regret for Princess Kate coverage

On March 22, Princess Kate shared that she was diagnosed with cancer following her abdominal surgery, leading numerous celebrities to express remorse over their prior comments about her.

On "The Late Show" last week, Stephen Colbert addressed his earlier jokes about the "mystery" of Princess Kate's "disappearance," saying he never intends to "make light of somebody else's tragedy."

Andy Cohenapologizes, denies sexually harassing Brandi Glanville in 2022 video call

"Far too many of us know that any cancer diagnosis of any kind is harrowing for the patient and for their family," he said. "Though I'm sure they don't need it from me, I and everyone here at the 'Late Show' would like to extend our well-wishes and heartfelt hope that her recovery is swift and thorough."

The hosts of "The View" also expressed regret for how they talked about Princess Kate's absence. In a previous segment, co-host Sunny Hostin suggested the TMZ video showed a "body double" of Kate, and Alyssa Farah Griffin agreed there was "some question" about whether it was really her.

"I felt awful," Griffin said after the cancer announcement. "I'm guilty of having gotten into the fun of 'Where's Kate?' and sort of thinking it's funny and sharing the memes and playing into that."

But after Whoopi Goldberg had repeatedly defended Princess Kate on the show, co-host Ana Navarro said, "The lesson I learned was when Whoopi Goldberg tells me to mind my own damn business, I will mind my own damn business from now on."