Religious Humor?

Well, not exactly. But, one of my co-workers and I have been amusing ourselves by making comparisons/similes that end with "a nun's box."

For example:

"This new car is as roomy as a nun's box."
"Ben Wallace's afro is as nappy as a nun's box."
"Your toddler bites harder than a nun's box."

And etc. Yeah, we're children. No, it's not sophisticated. No, it's not always funny. But since when have I ever been known any of that high-minded stuff? Besides, my lunch and the temperature in this office has me stuffed and hotter than a nun's box. I gotta keep myself awake somehow.