Gavin Rossdale is reportedly unhappy about how close his three children have grown to Blake Shelton.

Photo: Gavin Rossdale Reunites With Nanny Mindy Mann At Her California Daycare?

As Shelton's romance with Gwen Stefani becomes more and more serious, so does his relationship with her boys, and unfortunately, that hasn't sat well with Rossdale.

“Blake is amazing with the kids. He’s such a big kid himself and loves doing all the same things as they do,” an insider told Hollywood Life. “One of his favorite things to do with them is go on hikes — they love Malibu Creek. They get out there in the mud, hunting for frogs or playing hide-and-seek. Blake loves any excuse to get outside and get dirty, so he’s a big hit with Gwen’s kids. It drives Gavin nuts that his kids have bonded with Blake. He hates that they’re spending so much time with him. He doesn’t have any say in it…and it’s killing him.”

You'll Never Believe How Well Gavin Rossdale Made Out With His Divorce From Gwen Stefani

In November of last year, months after Rossdale and Stefani parted ways, an Us Weekly report claimed Rossdale had been engaged in a three-year affair with the nanny of their three sons, Kingston, 9, Zuma, 7, and Apollo, 2. And although the couple never publicly addressed the rumors, Rossdale was spotted at Mindy Mann's daycare center, as revealed by the Daily Mail, less than one month after the affair report was published.

Tags: Gwen Stefani gavin rossdale mindy mann