At what point does it become acceptable for a student to date a teacher? It's obviously a no-no if the student is underage, but some colleges have banned student-teacher sex completely, even between consenting adults. For years, the topic has fascinated filmmakers and viewers alike. Some are particularly racy takes on these scandals, like the film A Teacher, while other affairs are explained more easily — Drew Barrymore is an undercover reporter in Never Been Kissed, therefore technically fair game ( . . . still a little shady). Here are student-teacher liaisons that cross the line from cute to questionable.