The relationship is legally permissible if the educator and student were married when the sexual relationship occurred. It is also acceptable if the relationship began before the acceptance of employment and the age disparity between the educator and student is no more than three years.

Why is it illegal for teachers to date students?

Because teachers are in a position of authority over their students. The law doesnt want a teacher having a sexual relationship, or any romantic relationship at all, with a student. College professors even get fired for it.