The 55-year-old Bush frontman wasted no time to do a quick change after his lesson over the weekend left him completely drenched in sweat.
The No Doubt singer's ex couldn't wait to rip off his wet gray t-shirt and flex for the cameras nearby.
Gavin beat up the ball on Saturday at a Los Angeles court but made sure to get in a quick stretch before his lesson began.
The rocker sported an interesting wardrobe combination, wearing camouflage print shorts, a plain tee, bright pink socks, and a scarf to hold his long locks out of his face.
Doing lunges before getting into the tennis ball, Gavin's cool fashion choice didn't stand a chance in the Southern California heat.
Within minutes, Gwen's ex-husband was drenched in sweat -- which was evident, thanks to his gray-colored shirt.
Gavin didn't seem to mind because after rocking his sweat all over his chest for nearly an hour, the musician finally gave fans what they wanted and opted to go shirtless.
Showing his former wife what she's missing, the Bush singer proved he's still got it.
Rocking a buffer version of the dad bod, Gavin flashed a smirk towards the cameras before putting on a white t-shirt to leave his lesson.
Gavin's shirtless tennis lesson comes just weeks after his icy reunion with Gwen.
As Radar reported, the exes ignored each other at their son's football game only weeks after she walked down the aisle with Blake Shelton.
The duo did not seem friendly and made sure to keep their distance, despite co-parenting since their divorce in 2015. Maybe Gavin's holding onto some animosity, considering Gwen met Blake that same year.
Photographers were close-by to capture the awkward moment between Gavin and Gwen, who share three sons -- Kingston, 15, Zuma, 12, and Apollo, 7.
Last month, Gwen became Mrs. Blake Shelton in an intimate wedding that didn't include many of their famous friends.
As Radar exclusively reported, Blake's TV bestie Adam Levine didn't even make the guest list. Sources revealed the Maroon 5 frontman found out about his buddy's wedding like everyone else -- through the media.
“Adam had no idea when Gwen and Blake very going to get married. Adam wasn’t invited to the wedding and was not given the heads up despite the fact that Blake and Adam used to be as close as brothers when they were both on The Voice together,” our insiders said at the time.
Blake later proved he has no regrets about his wedding list. He spoke out about the friends -- like Adam -- who got snubbed during a recent podcast, telling them to "get over it."