All in the Family S02E17 - Mike's Mysterious Son

Edith answers the door to find a woman on the stoop with a young boy. The woman casually mentions that she's dropping Mike's son off and promptly leaves. Edith now finds herself in the awkward position of explaining to the rest of the family where the boy came from. When he finds out, a stunned Mike doesn't know what to say, but does admit to Gloria that he had been intimate with the boy's mother.