An obstacle course

Adam was in the locker room when one of his classmates, Alex walked up to him. Adam was in his boxers while Alex was in his shorts. “You here we're doing the obstacles coarse today?” Alex asked slipping on his shirt. Adam shook his head sliding on his shorts. “How about we make this interesting” Alex said looking at Adam.

“What do you mean?” Adam look confused

“Well I mean how about we make a bet?”

“I’m listening.”

“Well, I was thinking, first off we wear these.” Alex pulls out two thongs, “Just for an extra challenge.”