The couple has officially brought their romance center stage on The Voice and their flirting has only intensified since last week's live taping, specifically off-camera.
"Right when they called for the break, Blake ran over to Gwen's chair. They were talking close and laughing until makeup duties called," an onlooker told PEOPLE.
And even before the live show kicked off, Stefani, 46, and Shelton, 39, had the audience hollering. The mother of three ran to her country crooner's arms after being welcomed on set, much to their fans' delight.
This week's round of Stefani-Shelton flirtation had even Adam Levine and Pharrell Williams at a loss for words, specifically during contestant Amy Vachal's acoustic remix of Drake's "Hotline Bling."
"I don't think there's ever been a more elegant and classy performance of a song about a booty call in the history of music," Shelton said after the performance. "I mean that was, like, unbelievable. I hear that song on the radio every day. That song’s so big even I have heard it."
"You know that song?" Levine uttered before his BFF Blake added, "Gwen sang it to me on the Tonight Show one night, so..."
Cue audience hoot and holler.
And when the camera panned to the rest of the coaches, Stefani wasn't the only one flustered. "Okay, this is your moment... Wow," Williams said in an attempt to get the attention back on the singing talent.
It seemed Stefani and Shelton could not get out off set fast enough as "both just sprinted backstage together."