Get the details on how Michael B. Jordan pranked his That Awkward Moment costars Zac Efron and Miles Teller -- plus, find out how Teller retaliated Credit: Eric Charbonneau/Invision for Focus Features/AP Images

That awkward moment when your costar takes off his towel and has absolutely nothing underneath... Michael B. Jordan was supposed to be wearing a modesty sock while filming a scene in That Awkward Moment where he shows Miles Teller and Zac Efron his nether regions -- there's a reason for it in the movie -- but as a practical joke of sorts, he decided to just go commando and flash them the real deal.

"I said, 'F--k it. Why not make it awkward on them?'" Jordan, 26, joked with Us Weekly at the L.A. premiere of the comedy on Monday, Jan. 27. "I was fine! I was completely comfortable."

Indeed, Teller told Us at the same event that his costar was perfectly happy going au natural -- especially if it rattled his buds. "You know, Michael B. is very comfortable walking around on set naked," the Spectacular Now star, also 26, quipped. "It's a lot to deal with when you've just met a guy, but, yes, he enjoys taking his pants off." 

As does Teller, apparently. "I mean, it wasn't appropriate for my character, so I didn't, but I'll moon people," he told Us. "I think mooning is really funny and I think it should come back."

That said, messing with someone's mind can be just as entertaining. "Every day on set when we had a comedic scene, I looked in [Michael B.'s] eyes and said, 'I know you're scared because you've only done drama,'" Teller told Us of Jordan, who is known for more serious roles in Fruitvale Station, Friday Night Lights, and The Wire. "I said, 'But don't worry about it. Hold my hand, little girl.'"