BLAKE SHELTON’s latest badboy behavior may be the final straw for his hot-tempered honey, Miranda Lambert!

The country crooner and “Voice” coach has been flirting up a storm with 21-year-old Team Blake member Audra McLaughlin – and he even implied the shapely stun­ner is a better singer than his wife.

“Blake has sunk to a new low,” said an insider. “Miranda has almost come to grips with Blake’s persistent wandering eye.

“But she’s in shock that he’s telling Audra she’s as good as, if not a better singer, than Miranda.

“Poor Miranda always comforted herself knowing that through their nastiest fights, and even if she gained a few pounds, Blake would always at least respect her incredible musical talents.

“But it seems like Blake has no shame and doesn’t care that he’s humiliating his wife on national TV.”

Philadelphia-based Audra first caught 37-year-old Blake’s eye during audition rounds of the sixth season of the hit NBC singing competition. For her tryout, Audra sang “Angel From Montgomery,” a song Bonnie Raitt made famous in 1974. Her performance turned all four judges’ chairs.

After wooing Audra to his team, Blake gushed: “Audra is absolutely amazing. That’s one of Miranda’s all-time favorite songs. She took it to a place that Miranda doesn’t take it.”

As Blake raved, Audra giggled, appearing to eat up every one of his compliments – and she then chose him as her mentor.

BUT Blake’s OVER-THE-TOP praise apparently left Miranda fuming.

“She lit into him, demanding to know if he truly thought an amateur wannabe could rival her singing chops,” the source said. “Blake tried to reason that it’s his job to help build up the singers to give them confidence. But Miranda wasn’t buying it. She told Blake he’s on his last lifeline.

“She’s been watching Audra and Blake like a hawk. If Miranda sees anything that leads her to believe they’ve crossed the line, I’ll bet she’s ready to file divorce papers.”

This isn’t the first time the “Automatic” singer has been upset by her hubby’s flirty relationships with beautiful women. According to sources, she blew up over his friendships with young singers Cady Groves and Cassadee Pope, and last fall she exploded again when Blake was photographed with his arm around actress Lindsey Sporrer at a birthday party for his fellow “Voice” mentor Usher.

Miranda – who recently dropped 35 pounds in a bid to save her nearly three-year marriage – also read Blake the riot act for getting too chummy with his “Voice” co-stars Christina Aguilera and Shakira.

“Now Miranda has ordered Blake to dial back his onscreen flattery of Audra,” revealed the source. “She told him that it’s one thing to disrespect her in their daily life, but it’s entirely unacceptable to humiliate her on prime-time TV.”