
Continuity mistake: After Topanga draws a lipstick heart around her face and Shawn says "Use a mirror, babe," a closeup is shown of Topanga smiling at Shawn and you can see Cory has lipstick on his forehead before Topanga has drawn it on him. (00:20:30)
Answer: That was what I hope was only a phase of the way things were in California at that time. Many kids who had parents who liked to be modern and be friends more than parents to their kids had them call them by their first names.
papajim