Jimmy Fallon knows celebrities' secrets. The hilarious Saturday Night Live alum transformed into entertainment correspondent Peggy Hess on The Tonight Show on Wednesday, June 10, to read stars' thoughts in a special Celebrity Whispers segment.

"Do you ever wonder what celebrities are whispering to each other when they're on the red carpet or at press conferences or any of that stuff?" Fallon, 40, began. "We have too, and that's why we sent our entertainment correspondent from the UK, Mr. Peggy Hess, with his highly sensitive microphones to get to the bottom of it."

Fallon then introduced Celebrity Whispers, which featured the star as a British personality complete with a coiffed hairdo and a posh accent. As B-roll of stars on the red carpet was shown, Fallon-as-Hess narrated their conversations, taking a stab at just what was being said between the Hollywood heavyweights.

Jessica Chastain was shown embracing her Interstellar costar Matthew McConaughey and doing a little dance. "Hey, I'm so excited. I made up a new song today," Fallon's Chastain whispered. "Wow, you did?" McConaughey shot back. "Yes, I did... It's like, 'Don't go chasing waterfalls, please stick to the rivers and the lakes that you're used to,' and then it goes on like that." 

In another clip, Fallon imagines an awkward encounter between British supermodels Cara Delevingne and Kate Moss. "Knock knock," says Moss to her heir apparent. "Who's there?" responds Delevingne. "Interrupting cow," says Moss. "What? Interrupting cow who? What are you talking about? What?" says Delevingne. "Whoops, I forgot to interrupt you!" exclaims Moss.

See priceless conversations with Jack Black, Dwayne "The Rock" Johnson, and Emily Blunt in the video above!