When you are a fresh new Professor, you have too much sympathy for your students. You give another chance to Marilyn and Lilly, the naughty and the nice, to pass your course. They both came prepared but in different ways. As Lilly answers the questions like a good girl, the bad girl Marilyn has something else to offer for a passing grade. How about touching her boobs for an additional point or two? She can let you fill her pussy instead of filling that boring exam paper. This way seems easy to Lilly as well.