George Romney had kids, huh?
Kind of, unless you believe the conspiracy theories.
The mystery is that no one had ever heard of a "Mitt" Romney, or seen a child from the Romney parents, and then one day a 14 year old, fully formed male, walked out under his own power from the American Motors Laboratories, and said, "Hi, I'm Mitt Romney, where is daddy?", there were suspicions for a while, but I haven't heard that brought up in decades.