Gwen Stefani and Blake Shelton's infectious connection was back on display on The Voice's "Best of the Blind Auditions" episode on Wednesday.
Stefani is on a break from coaching as she releases new music, but the singer is making regular appearances as an advisor to Shelton's team.
Before they get down to business, the superstar couple can't help but flirt as the cameras roll. "Hi," Stefani, 46, says to Shelton, 39, with a big smile, to which Shelton replies, "What's up? [You're] a rock and roll goddess, diva, legend."
"Whoa," Stefani replies as her grin deepens. "What?!"
Then Shelton gets serious, explaining why Stefani is the ideal advisor. "I brought Gwen in because if there's anybody who understands what a battle round is, it's somebody who has been a coach." And he later praises her for helping two competitors with a pop song, remarking, "This is the moment right now that I really wanted her to be my mentor. Y'all know I have a bunch of country artists, and when it comes to you two, I'm like [gasping], 'Gwen. Gwen, will you help me?'"
The duo – who famously hit it off during Season 9 – have already taken their spark to the recording studio. The resulting duet is expected to appear on the country star's forthcoming album, a source told PEOPLE exclusively this month.