They want it that way.

Mila Kunis and Ashton Kutcher showed rare PDA while enjoying the Backstreet Boys’ larger-than-life “Into the Millennium” summer residency at the Sphere in Las Vegas.

A fan captured a video of the longtime couple enthusiastically singing and dancing to the band’s 1999 hit song “I Want It That Way” during the sold-out concert on Saturday.

Kunis, 41, and Kutcher, 47, were spotted belting out the lyrics to each other while dramatically waving their arms around.

At one point, the “Bad Moms” actress pulled her husband in closer before Kutcher grabbed her around the waist.

The “Two and a Half Men” alum then passionately put his hands on her face as they continued their mini performance from their suite.

The loved-up pair also wore coordinating colors for their date night at the pop concert.

“Ashton Kutcher and the ever-lovely Mila Kunis were behind us at the Backstreet Boys show at the Sphere tonight,” the Instagram user captioned the upload on Instagram.

“They stole the show on this one with a little fun. They were both gracious to the crowd and fans around them.”

Kunis and Kutcher began dating in 2012 and tied the knot in 2015 — years after meeting and co-starring together on “That ’70s Show.”

They share two kids: daughter Wyatt, 10, and son Dimitri, 8.

Last month, People reported that the couple celebrated their 10-year wedding anniversary during a trip to Venice, Italy.