School locker help? please answer!?

Ok so i took my locker home and i forgot to bring it to school today so the pincible locked my locker with a lock so no one can get into my locker. to get it open i have to ask him to unlock it for me but i dont have enough time to go ask him or else ill get a detention when should i go and ask can you give me a good excuse that i can say to my homeroom teacher to convince her i really need my stuff in my locker