This may have been around before..

Two Irish nuns were sitting at traffic light in their car when a bunch of rowdy drunks pulls up alongside of them.

"Hey, show us your boobs, ye bloody penguins!" shouts one of the drunks.

The Mother Superior turns to Sister Immaculata, "I don't think they know who we are - show them your cross."

So Sister Immaculata rolls down her window and shouts, "Screw off ye little fookin wankers, before I come over there and rip yer balls off!"

Sister Immaculata looks back at the Mother Superior and asks, "Was that cross enough?"