Opps! A slip of the tongue

Since it is the beginnning of exam week, i dont have much to report on for this week except for......
It was the end of a very long day and i was with my home room class, checking the roll, making sure girls had put their chairs on their desks and had their blazers and berets on before leaving school. Then i notice a pile of rubbish at the back of the classroom. I said in a loud voice: "year eight, make sure this room is neat and tidy before you leave, and can some one remove all that crap at the back there." it was a slip of the tongue.....but the response from the girls was priceless. they were so suprised, lots giggled we all had a bit of a laugh and i was red with embarassment.