John Stamos' "Grandfathered" co-star Josh Peck (not pictured) joined him at the Teen Choice Awards on Sunday, Aug. 16, 2015. Getty

It wouldn't be a full house without Uncle Jesse. Josh Peck donned a black leather jacket and fake Uncle Jesse hair when he interrupted John Stamos at the 2015 Teen Choice Awards.

Uncle Josh vs. Uncle Jessie #TeenChoiceAwards

Stamos was telling the crowd that he'd give Peck a six or a seven rating for his job hosting the awards when Peck slid next to Stamos dressed up as the "Full House" character.

"You're going to go there, you're going with the Jesse wig huh?" Stamos asked his "Grandfathered" co-star.

"Who wore it best Uncle Josh or Uncle Jesse?" Peck asked the crowd before telling Stamos to "cut it out." Stamos retaliated by throwing one of Peck's catch phrases back at him by saying "I ain't calling you a truther," when Peck asked if he was calling him a liar.

Peck and Stamos will be appearing together on Fox's upcoming show "Grandfathered," which premieres Sept. 29 at 8 p.m. EDT.