Need Samples

An old man goes to the doctor for his yearly physical, his wife tagging along. When the doctor enters the examination room, he tells the old man, "I need a urine sample, a stool sample and a sperm sample."

The old man, being hard of hearing, looks at his wife and yells: "WHAT?"

"What did he say? What's he want?"

His wife yells back, "He needs your underwear."