John Stamos’ birthday shout-out to Glen Powell had fans exclaiming, “Have mercy!”

The former “Scream Queens” star shared a series of cheeky photos on Instagram Tuesday to celebrate Powell’s 37th birthday.

“Happy Birthday @glenpowell, the man who’s witnessed me in the buff more times than I’d care to confess,” wrote the 62-year-old “Fuller House” star.

He added, “Love you buddy! Steam room date soon? xo JS.”

The first image in the carousel shows Stamos and Powell strolling down the street wearing nothing but sandals, modestly hiding behind a skateboard and shopping bags.

They were joined by Taylor Lautner in the subsequent shot as the trio stood smiling in showers.

The slideshow concluded with pictures of Stamos and Powell in a steam room, covering up with towels in the first snap and black shorts in the second.

“The best,” Lautner, 33, commented on the post.

Fans raved over the images, with one writing that Stamos’ upload was “more like a happy birthday to us” — and many quoting his “Fuller House” character, Jesse Katsopolis, with, “Have mercy.”

The “Grandfathered” alum has a history of celebrating his own birthday sans clothes.

When Stamos turned 54 in 2017, he shared a cheeky photo of himself taking an outdoor shower among palm fronds.

“54 and clean,” he wrote at the time.

Six years later, he turned 60 with another steamy shower snap taken by his wife, Caitlin McHugh.

“The other side of 60,” Stamos captioned the photo of himself covering up with one hand.

He and McHugh, 39, have been married since February 2018 and share a 7-year-old son named Billy.