What Size Am I?

The first time I went to a drug store to buy condoms, I was waited on by a beautiful young woman.

She asked what size I wanted and I said I wasn't sure. So she asked how big I was and I said, "Compared to what?"

She held up one finger and asked if I was that big. I said,

"I'm bigger than that."

Then she held up two fingers and asked if I was that big. I said,

"I'm bigger than that."

Then she held up three fingers and asked if I was that big. I said,

"I'm about that big."

She put the three fingers in her mouth and said,

"You're a medium."