• John Stamos has worn vintage Jonas Brothers tour merch multiple times.
  • Nick Jonas recently took notice and wore a sweatshirt featuring a photo of the “Full House” star, writing, “It’s your move @johnstamos.”
  • Since then, the stars have been continually trying to one-up each other.
  • Now, Stamos seems to have escalated the prank war by getting a tattoo of Jonas’s face – though it’s likely that the ink is fake.

John Stamos apparently has quite the collection of vintage Jonas Brothers tour merch and the youngest member of the band recently took notice, igniting an elaborate prank war between the two men.

Nick Jonas recently stepped out wearing a sweatshirt that prominently features a photo of Stamos. In the photo on the sweatshirt, taken on July 3, 2018, Stamos is wearing a Jonas Brothers t-shirt.

nick jonas john stamos sweatshirt

Foto: John Stamos at the 2018 A Capitol Fourth rehearsals; Nick Jonas earlier this week.sourcePaul Morigi/Getty Images for Capital Concerts Inc. / @nickjonas/Instagram

The photo from Jonas’s shirt isn’t the only time Stamos has been spotted wearing Jonas Brothers merchandise: He also rocked a shirt from the band’s 2009 world tour at the 2018 American Music Awards.

But when Jonas posted a photo of himself wearing the sweatshirt on Instagram, adding the caption, "It's your move @johnstamos," he incited a series of stunts that has rapidly escalated.

Not to be outdone, Stamos upped the ante with a pillowcase that features the very same photo that Jonas posted on Instagram.

"Had the craziest dream last night..." he captioned the shot on Twitter.

"Bravo," conceded the official Jonas Brothers Twitter account - but the two have continued to go back and forth.

Soon after, Jonas posted a similar photo of himself sleeping, but the photo of Stamos had been blown up and printed on his bedspread.

"I'll sleep well tonight knowing #sucker is number 1!" he wrote, referring to the Jonas Brothers' recently released single, which is their first as a band since 2009.

http://instagr.am/p/Bu4_Uq-F_d4

On Saturday, Stamos took things to the next level when he posted a photo that appears to show the actor getting Jonas's face tattooed.

"#jobrosforlife," the caption reads.

"Okay... okay..." Jonas commented.

http://instagr.am/p/BvDSF_YhNIM

The two older Jonas Brothers even praised Stamos in the comments. Joe Jonas simply commented with eight crying-laughing emojis, while Kevin Jonas wrote, "No way!!!!"

Of course, Stamos doesn't appear to have any other large tattoos, so it's certainly possible that the ink is fake, staged for the sake of a game-changing stunt.

INSIDER will keep this post updated with any further developments.