Last Man on Earth EXTENDED

He is the last man on earth. The women keep him naked in a cage and school girls come to look at him for field trips. Dr Kenna Valentina is the foremost authority on men and is giving a tour to a teacher and two of her honor students, (Part 1 Masturbation instruction POV)The girls are amazed at the sight of the man and are fascinated by his penis. They see it stand up and as things are explained to them they get even more excited and start encouraging him to stroke and jerk the huge thing between his legs. The girls are overjoyed and amazed when it erupts with white goo (Part 2 handjob) The man seems to need a lot of attention to his penis so Doctor Kenna decides it will be ok for the teacher and her students to play with it. Then girls are so curious and so happy and when it erupts again they are overjoyed!