"She turned around looking semi-shocked that he did that and laughed and smiled," an onlooker told PEOPLE.

Credit: Twitter

In this week’s edition of Blake Shelton and Gwen Stefani PDA, there’s kissing and cheeky shoulder biting.

While The Voice costars have yet to talk in detail about their relationship, their actions continue to speak louder than words. Case in point: part one of the live semi-final performances on Monday.

“Blake came up to Gwen from behind and kissed her on the head. It was so cute!” an onlooker told PEOPLE. “She turned around looking semi-shocked that he did that.”

In between breaks, the couple appeared to be more inseparable than ever giving the audience plenty of opportunities to ooh and aah.

And during Ellie Goulding‘s pre-taped performance, Stefani and Shelton were joined by Adam Levine and Pharrell Williams for a group selfie, during which the country crooner showcased his flirty side.

While the rest of the cast made funny faces, Shelton adorably pretended to bite his girlfriend’s shoulder. The cute snap was later shared on her Twitter page.

Shelton and Stefani began dating in early November months after she ended her 13 year-marriage to ex Gavin Rossdale. Shelton and Miranda Lambert announced their divorce this summer as well, after four years of marriage.

Recently, the couple dodged questions about their relationship status during a joint interview with Today‘s Natalie Morales. Good thing for them, Levine and Williams were also on hand to distract the attention away.

“Blake and Gwen we all know what’s going on with you guys, is it good to just be out in the open now?” Morales asked before the Maroon 5 frontman interjected and belted out: “Diversion! Distraction! Ask the next question before it gets awkward!”

Reporting by NICOLE SANDS