The Flintstones S03E08 - The Little Stranger

Fred overhears portions of a conversation that Wilma and Betty have about taking in a little visitor and stranger and Fred thinks Wilma is having a baby. He asks his mother-in-law to stay to help Wilma with the arrival of their baby. But, to Fred's chagrin, the "little visitor" turns out to be the Flintstones' paperboy, Arnold, and one of the sources of much of Fred's anger and frustration.