15 inches…

An innocent new bride went to her doctor for checkup. She asked the doctor "What's that thing hanging between my husband’s legs?"
The doctor replied "That’s the penis." The new bride then asks "What's that reddish thing on the end of penis?"
The doctor replied "That’s the head of the penis. The bride then asks "What are those 2 round things about 15 inches from the head of the penis?"
The doctor replied "Lady, on him I don't know, but on me they're the cheeks of my ass!"