Gavin Rossdale doesn’t allegedly have any plans to get on Blake Shelton’s good side.

In its March 14 issue, National Enquirer claimed that Gwen Stefani’s ex-husband is trying to upset Shelton every chance he gets.

And Rossdale knows that there’s no better way to make Shelton angry than by suggesting that he has poor fashion sense and that he should focus on his diet.

“Gavin’s the real troublemaker here. He teases Blake to no end, referring to Gwen as ‘my beautiful ex-wife.’ He has this way of getting under Blake’s skin,” the source said.

The source said that Rossdale also offered Shelton tips on how he could look better just to piss him off.

“Lately, Gavin’s offered to be Blake’s fashion and diet guru because the guy’s put on a few pounds and can’t seem to wear anything besides dad jeans and boring shirts. Bottom line, he feels Blake’s not good enough for Gwen and wants to stick it to him any way he can,” the source said.

However, the insider said that Shelton isn’t backing down from Rossdale. And he’s even thinking of ways how he could get even with Stefani’s ex-husband.

“Blake is very alpha-male so he’d never show it bothers him, but it absolutely does. Just the mention of Gavin’s name sends a dark look across his face,” the source said.

Additionally, Rossdale is also upset with Shelton because of how close he is to the former’s sons.

“That’s a big part of why Gavin goads him. He wants to be sure Blake knows his place,” the source said.

This isn’t the first time that Rossdale and Shelton were pitted against each other.

In September, Star claimed that Rossdale is struggling to move on from Stefani. So, seeing his ex-wife with Shelton most definitely hurts.

At one point, another publication claimed that Rossdale decided to date a woman that resembles Stefani because this is as close as he could get to his ex-wife.

But when the No Doubt singer found out what Rossdale did, she was allegedly creeped out. After all, it was Rossdale that ended their marriage because he cheated on Stefani.

However, one should take the tabloid’s claims with a grain of salt.

After all, there’s no indication that Rossdale is still hung up on Stefani or that he’s feuding with Shelton.