Taylor Swift isn't the only country star with major beef against John Mayer. Judging by a string of recent Twitter comments made by country rocker Shooter Jennings, the son of country legend Waylon Jennings isn't too keen on the 'Shadow Days' singer either, going as far to call the pop hitmaker "king douche."

"I love how the 'neil young of our generation' self-naming king douche grows his hair out + buys a place in Montana just to do [Rolling Stone] article," Jennings tweeted.

The outspoken singer continued his technological tirade in more depth, saying, "Claims he's 'done w hollywood game' and has 'roots' and then immediately cuts hair, goes back to hollywood clubs + starts banging Katy Perry."

"And don't anybody say he's a great guitar player. Gary Clark Jr & [Lukas Nelson] wipes their a--es with this dude," Jennings declared.

After cooling down a bit, Jennings apologized, clarifying the reason for his angry rant. "Sorry to s--t talk. Lord knows not everybody likes my a--," he wrote, adding, "But seeing that RS in my friggin bathroom & reading the narcissistic drivel..."

The famed Rolling Stone article Jennings is referring to ran earlier this year, with Mayer claiming he had finally shrugged off the Hollywood lifestyle to focus on honing in on his own musical identity. Fast forward six months later, it seems as though the singer has rekindled with his old ways, allowing his relationship with the recently-divorced pop singer (Perry) to overshadow his recent album release, 'Born and Raised.'

As for Swift's disdain for her former flame, well, she's made that fairly common knowledge -- at least in song -- but Jennings' recent outburst seems to come completely out of left field. Could it be that 'The Real Me' singer is coming to the defense of his fellow country superstar? Or maybe this is just the first round of punches in another Hollywood feud?