Blake Shelton and Gwen Stefani heated up romance rumors on the sets of "The Voice" with their "hardcore flirting," despite denying reports that they are dating, Hollywood Life reported. The report comes amid Shelton’s comments about his former wife, Miranda Lambert, that they are “buddies.”

During the show’s latest episode, Stefani and Shelton seemed to be having a lot of fun with each other and complimented one another. Stefani told the "Sangria" singer that "when you’re sweet, you’re sweet," to which Shelton replied: "That’s the nicest thing you’ve ever said to me."

In another instance, Shelton got up and danced in front of Stefani’s chair. Gavin Rossdale’s former wife, Stefani, cheered for Shelton and reportedly said that he should go up on stage and "do that" for the audience.

Also, when Stefani praised a contestant saying, "The fact that you're 16 and you can lock eyes with me and be that brave…," Shelton remarked: "That is against the rules what you're doing right now. Foul!"

"I want to say thank you for locking eyes with me…" Stefani continued, before being interrupted again by the country singer. "That is indefensible," Shelton yelled.

Earlier reports surfaced that Shelton was constantly flirting with Stefani to make his former wife jealous.

"It’s not romantic, but that doesn’t mean they can’t participate in some good natured flirting," a source told Hollywood Life. "Blake can’t help himself, he’s a natural flirt and Gwen is adorable. Part of him hopes that seeing him looking so fit and working so close with a knock out like Gwen makes Miranda jealous."

Shelton, 39, and Lambert, 31, who were married for four years, went public with their divorce in late July. Shelton’s divorce woes were reportedly cited as a reason for his close relationship with Stefani, as the two have been going through the same phase. Stefani filed for divorce from Rossdale in August, ending their 13-year marriage.