AceShowbiz - Blake Shelton apparently feels sidelined amid Gwen Stefani's new friendship with Carly Pearce. The country music crooner is reportedly jealous over his wife's close bond with the newly-single Indiana native.

"Carly struck up a close friendship with Gwen while she was on tour with Blake," a so-called insider spilled the beans to Radar Online. "They found they have so much in common and really hit it off."

Gwen and Carly reportedly grew inseparable particularly since Carly's breakup with real estate agent Riley King in early June. "Gwen's been Carly's biggest supporter, telling her she deserves the best and it's okay to wait for the right guy, like she did," the source dished.

Since then, Gwen and Carly would "go off for girls' nights on the town, hang out and get silly, and Blake's taken about all he can," according to the insider. The source added of Blake's reaction, "There's a tinge of jealousy there because Carly was his friend first."

The "Austin" hitmaker allegedly would rather the two ladies give it a break or at least include him in their shenanigans, but "he's too proud to make a huge stink." The source revealed, "He's venting to pals, asking why he left 'The Voice' only to be treated like dog meat at home."

Carly has previously raved over her new pal Gwen. "I love her," she told Entertainment Tonight in April, ahead of their joint performance at the CMT Music Awards on Sunday in Austin, Texas. "I've gotten to know her pretty well being on tour with Blake and she just is a true fan of songwriting, just like me."

"Just to be able to come together and have a real moment with somebody that you've gotten to know -- it's not just a collaboration out of nowhere -- it's going to be fun," she added of their gig at the awards-giving event. Carly also opened for Blake on his "Back to the Honky Tonk Tour" which kicked off in February and ran through March.