A Jewish boy was walking with his girlfriend on the grounds of his 
father's house. His father was a successful doctor, and was carrying out
a circumcision in the on-site surgery. As they were walking, they heard
a scream and a foreskin flew out of the window and landed at the girl's 
feet.
"What's this," she asked.
"Taste it," he replied, "If you like it, I'll give you a whole one!"