A matchmaker goes to see Mr. Henderson, a confirmed bachelor for many years.
"Mr. Henderson, don't leave it too late," she pleads, "I have exactly the one you need. You only have to say the word and you'll meet and be married in no time!"
"Don't bother," replies Mr. Henderson, "I have two sisters at home who look after all my needs."
"That's all well and good but all the sisters in the world cannot fill the role of a wife," the matchmaker replies.
"I said 'two sisters,'" Mr. Henderson responds: "I didn't say they were mine."