John Stamos showed off his abs in a shirtless selfie posted to Instagram on Aug. 24 Credit: Courtesy of John Stamos; Allen Berezovsky/WireImage

Is it just Us, or is John Stamos getting hotter as he gets older? The Full House alum, 51, set hearts aflutter for the umpteenth time on Sunday, Aug. 24, when he took to Instagram to share a picture of himself in all his shirtless glory.

The photo shows Stamos standing in front of a mirror, wearing only a pair of low-slung bottoms. His face is covered by his phone and the flash of the camera, but his abs, chest, and arms are on full display.

"51 no filters F' it," the Necessary Roughness actor captioned the sexy selfie, which racked up more than 28,000 "likes" in the 13 hours after it was posted.

Stamos has good reason to be confident. During an appearance on The Talk last year, he revealed that he takes Pilates classes to stay in shape. "I'm the only guy in there. They plot before I get there, like 'how can we make John look ridiculous?'" he quipped.

He went on to poke fun at some of the poses, joking that they generally involve his legs up in the air. The payoff makes it all worth it, though. "The good thing is, I have a beautiful woman's body now," he deadpanned. "I have a great ass now."