Country royalty may have gone gaga for the Backstreet Boys at the Academy of Country Music Awards in Las Vegas on Sunday, but pop princess Britney Spears kicked the weekend's Backstreet fever into full effect at her Piece of Me show the night before!
The songstress is known for pulling an audience member on stage while performing "Freakshow" at her residency show at Planet Hollywood's AXIS Theater, so when BSB members Howie Dorough and Brian Littrell showed up to Saturday's concert, it was inevitable that one of them would find themselves on all fours.
Dorough took the bait, joining the 35-year-old "Slumber Party" singer on stage.
And while the stage is familiar territory for the 43-year-old father-of-three -- having recently launched BSB's Larger Than Life residency in the same venue -- let's just say he pulled some slightly naughtier moves than fans are used to seeing him perform.
Getting down on his knees as Spears clutched him via a leash, the "100" crooner took a nervous look behind him before plopping down onto all fours and crawling along the catwalk as she tapped him on the butt with a whip.
The boy bander, whose gorgeous wife Leigh wasn't at the show, then stood up and showed off his sexy Latin dance moves, before Spears wrapped up the song and signed a t-shirt for him.
"Everyone give it up for Howie from the Backstreet Boys!" she exclaimed. "Thank you so much for coming out here and dancing with us. Everyone give it up for Howie!"
The band, who commence the next run of their residency on April 12, then shared a video of the epic showdown on their Instagram, crediting Spears for "bringing out the freakshow" in Dorough.
"Leave it to @BritneySpears to bring out the freakshow in Howie D!" they captioned the clip. "What happens in Vegas... #pieceofme #pieceofhowie #bsbvegas."
This isn't the first time a Backstreet Boy has made it into Spears' exclusive "Freakshow" club. Bandmate AJ McLean was also pulled on stage when he and Kevin Richardson attended the hitmaker's show last year.
Dorough's memorable moment was part of a big weekend for the GRAMMY-nominated band in Las Vegas, where they stole the show at the ACM Awards on Sunday.
Performing their collaborative ballad, "God, Your Mama, and Me," with country duo Florida Georgia Line, the quintet then had stars like Nicole Kidman, Tim McGraw and Carrie Underwood going nuts with excitement as they launched into their hit, "Everybody (Backstreet's Back)."
Following the performance, Florida Georgia Line filled in ET on how they had only learned BSB's dance moves just a few hours before the big show. Check out the video below.