It's the season for senior class pranks and for the most part, these harmless stunts go unnoticed. But one prank at Robbinsville High School has left one senior unable to walk with his class at graduation.

A graduate adjusts his cap.(Jens Schlueter/Getty Images)

Chris Smith tells he was part of a senior prank involving water guns being brought into the school during lunch. After some seniors brought their "weapons" into the building teachers locked the doors as part of a mandatory lockdown and warned that if anyone let in anyone else they would not be able to walk at graduation.

Smith says he didn't know that and managed to pry open the locked door and got in the building. Principal Molly C. Avery followed through with the threat and told Smith he could not walk in Friday's graduation ceremony.

Superintendent Steven Mayer did not comment directly about Smith to except to say that the lockdown was "one of those things that we did to make sure nobody slipped and fell or got hurt unintentionally."

Robbinsville  High School's 209 seniors will graduate on Friday at 6 p.m..