Rectal exam

A man goes to a proctologist for his very first rectal exam. The doc tells him to wait in the examination room. Once inside, the man notices three items on the desk: a tube of K-Y Jelly, a rubber glove, and a beer.

When the doctor comes in, the man says, "Look, Doc, this is my first exam. I know what the K-Y is for, and I know what the glove is for but what's the beer doing there?"

The doctor looks at the beer and turns red with anger. "Nurse", he screams. "I said a butt light."