Chuck Shriner, 17, said he was making good on a $5 dare during Saturday's ceremony at Bishop Verot High School in Fort Myers when he dropped to one knee and struck the prayer pose made famous by NFL star Tim Tebow, the Naples (Fla.) Daily News reported Friday.
Shriner said the audience erupted with laughter at what he thought was a bit of harmless fun to "make graduation memorable," but administrators soon told him he would no longer be receiving his diploma -- unless he cleaned the gymnasium after the event.
"They said what I did would give underclassmen inspiration to do something else that it might lead to something else," Shriner said. "So they were trying to set an example."
When Shriner finished cleaning the gym Monday, he said he discovered his mother, who is a teacher at the school, was the mastermind behind the punishment and had his diploma all along.
"It was all her idea," Shriner said.
"She was really mad," he said. "But I think it was worth it."