Watch Hoda Kotb reveal her least favorite TODAY guest ever

It takes a lot to ruffle Hoda Kotb, but on Tuesday's episode of "Watch What Happens Live," she revealed which guest on TODAY she was left feeling less than enthused about.

Andy Cohen briefly handed over his hosting duties to Hoda’s close friend and former co-host, Kathie Lee Gifford, who got to ask Hoda three uncomfortable questions — only one of which she was allowed to pass on, or in "WWHL" terms, plead the fifth.

"Hi, Hoda mama! I’m back and I’m going to cause some trouble," Kathie Lee said at the start of the segment.

She went straight for the money question right off the bat:

"Who do you think was my least favorite guest of all time?" Kathie Lee asked. "And I bet it was yours, too."

Hoda immediately knew who she was talking about: Frank Sinatra Jr.

Video: Hoda tried to set up Maria Shriver and Lenny Kravitz on live TV

"It was the worst guest we’ve ever had, bar none," Hoda laughed. "He came for his book — he had a book he was promoting — and he didn’t want to talk about it so we didn’t say anything! It was so weird."

Revisit the 2015 interview here:

Cohen said he could commiserate with Hoda and told a story about a time he produced a segment with actor Tina Louise.

Related: Today is the last day to score on Apple Airpods, Revlon hair tools and more!

"And she didn’t want to talk about 'Gilligan’s Island'! And I was like, 'Well, I don’t know where to go with this.'"

Kathie Lee went on to dish out another tough question — "When's the most you've ever been annoyed at me before we went on the air?" — to which Hoda took the opportunity to plead the fifth. That left one last question, for Hoda to name three of Kathie Lee's songs, and she tried her best to do so.

Some other highlights from "WWHL" included Hoda trying to set up Lenny Kravitz, who was also a guest on Cohen's show that night, with her close pal Maria Shriver.

"She’s all of it," Hoda gushed. "She is the whole package."

"Y’all just doing this right on live TV?" Kravitz laughed.

"Something to think about, Lenny. This is what we do here," Cohen quipped.

Related: She added that the ceremony will likely be “a little bit more intimate” than originally planned.

Hoda also weighed in when a member of the audience asked who from TODAY she would choose to officiate her wedding. Hoda and her fiancé, Joel Schiffman, officially delayed their nuptials amid the pandemic and are planning on tying the knot sometime next summer.

"I would have Jenna do it," she said. "She would be sweet. We’re still trying to figure out the timing of it."