Katlego Marite, 13, was dragged into a car while playing with two friends near his home in the Mpumalanga coal-mining city.
A Cape Town couple is believed to have been kidnapped by Isis.
In recent Facebook posts, Michael Hunt, 43, had referred to the singer as his “queen” and had spoken of “tak[ing] off” with her.
David and Louise Turpin pleaded not guilty on Thursday.
A man was subjected to a 50 hour kidnap ordeal, during which he was physically abused, stripped naked, tied up and threatened
Child brides are still a shocking reality in South Africa.