The Tonight Show host put the stars to the test with his “Best Friends Game,” where Fallon, 44, and Jessica Biel, 36, were asked questions about Timberlake, 37, and all three had to write down answers to them on their own blank cards. And the exchange was made infinitely more entertaining because Timberlake can’t speak after “severely bruising” his vocal cords.

The first question addressed the Grammy winner’s favorite rapper. The answer? Mase and Andre 3000. Biel’s answer was on point, but Fallon sadly guessed Run DMC.

Still, he had a chance to make a comeback! But he didn’t do so right away. He got the next question wrong, too. Timberlake’s favorite cocktail is a tequila mule, and not a gin and tonic as Fallon had thought. Again, Biel knew what to write!

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“You don’t like it? You don’t like what I do for you?” Fallon quipped when he response was rebuffed. “The beverages we make and have, that’s not fun for you?”

“I think it is fun, it’s just not the most fun,” Biel spoke for her better half, which prompted him to mouth, “Oh snap!”

Biel then explained how to make a tequila mule, and her hubby mouthed, “I love you.”

Fallon’s comeback was around the corner when he correctly guessed that Timberlake’s safe word is “pineapple.” Of course, Biel knew it, too, and she punched her host when she realized the secret was out.

“Things just got weird,” Timberlake mouthed.

The pièce de résistance? When Fallon correctly guessed the number his guest was thinking of between 1 and 5000. Biel, sadly, was nowhere close. In protest, she jokingly removed her wedding band, handed it to Fallon and walked off the stage.

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Despite the ring toss, Biel and Timberlake are going strong. Timberlake recently shared some secrets about their relationship in his first book, Hindsight: & All the Things I Can’t See in Front of Me.

To start, he and Biel had a meet-cute worthy of any of the rom-coms that they’ve appeared in. He also explains why they dated other people when they first started seeing each other. (We were “keeping ourselves safe from getting hurt,” he wrote.)

“When I met Jess, it was undeniable how beautiful she is,” he wrote in Hindsight, which came out Tuesday. He and The Sinner actress met at a party in Hollywood.

“I made some sort of sarcastic comment, really dry,” he explained. “Nobody got it except her. She laughed, and I noticed, all of a sudden, and in the way where you wonder if a person’s like you, if they have a very dry, dark sense of humor, too.”

Though he didn’t ask for her number that night, he kept thinking: “I’m kind of really interested in that girl. There was just something about that girl. Kind of interested in that girl. Goddamn it.”

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He continued, “I had to psych myself up. I had to remind myself that I was me — giving myself a pep talk, shadowboxing with myself, rubbing my own shoulders.”

They saw each other again when she came to a show during his FutureSex/LoveSounds tour. He offered her and her friends a ride on his tour bus, which is when he finally asked for her number and they started talking, according to the book.

“Then the Golden Globes came up, and that’s when we planned on seeing each other,” Timberlake wrote. “We were both still seeing other people, keeping ourselves safe from getting hurt, from really putting ourselves out there. It took a bit for both of us to admit to ourselves that we were really, really into each other.”

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After he came back from touring abroad they spent a month together. Then they decided to be exclusive, according to Hindsight.

“We’ve had a lot of unforgettable times,” Timberlake said. “She’s become a huge influence on my life, and I have such an admiration for her, especially seeing her as a mother now.”

He added, “But I had admiration for her before. She’s a very good writer. She’s a poet. She’s a tremendous actor. She’s funny. Very funny. And she’s one of the most patient people I’ve ever met… She changed me. She changed my life.”

Timberlake and Biel married in Puglia, Italy on Oct. 19, 2012.