Justin Timberlake appears on Jessica Biel's show: 'Belly's fake, hair's fake, mustache is real'

Jessica Biel plays a suburban housewife caught up in deadly drama in her new Hulu series, “Candy,” but as it turns out, her off-screen husband has a role in the true-crime series, too.

She and Justin Timberlake just teased his surprise appearance with on-set photos of the singer and actor in costume as a 1980s lawman.

"Watch out, Candy," Biel captioned a set of pics she shared on Instagram. "There’s a new sheriff in town."

The first photo shows a mustachioed Timberlake standing alongside his wife, who's decked out in an era-appropriate pale blue pantsuit, as she takes on the titular role of Candy Montgomery, a woman who was accused of murdering her friend Betty Gore in 1980.

The second pic gives fans a better look at Timberlake's drab brown and gray ensemble as he flashes both his badge and a much bigger waistline than usual.

Over on his own Instagram, Timberlake posted more shots, include a full-length pic of the pair side by side.

"Belly's fake, hair's fake, mustache is real," he wrote. "Meet Diffy."

That's the nickname for his character, who isn't actually the sheriff, but rather a deputy named Steve Deffibaugh. The real Deffibaugh worked on the criminal investigation into Gore's death.

Timberlake appears in the fourth episode of the limited series. And his appearance was all his idea, according to his wife, who offered him a peek at the scripts.

“That was all Justin,” she revealed in an interview with TV Guide, adding that he "fell in love with" the part.

“He so desperately wanted to play this part, and I genuinely thought he was joking,” she continued. "I was like, 'We have no money to pay you, you’re gonna be making scale.'"

JT’s response? "He’s like, 'I don’t care. I want to play this part,'" Biel said.

And so he did, and the leading lady he's been married to for nearly 10 years said his performance was a “really cool, fun surprise for even me.”