The Smiths were unable to conceive children and decided to use a surrogate father to start their family.
On the day the proxy father was to arrive, Mr. Smith kissed his wife goodbye and said, "Well, I'm off now. The man should be here soon."
Half an hour later, just by chance, a door-to-door baby photographer happened to ring the doorbell, hoping to make a sale.
"Good morning, Ma'am", he said, "I've come to..."