Volunteers

Mr. Adams stood behind his desk in front of the projector like he always did but then stepped in front of the desk, so he could be in full view of the students. He was attractive for his age quite well toned, and he always wore geeky glasses and a white button-down shirt.
"Today's lesson is about reproductive organs" some boys in the class snickered.
"They usually have me show a picture of a penis and a vagina on the projector but I've recently gotten several emails from concerned parents saying that they are concerned that their children are not getting a good enough idea of where each part is" The class was nervous, what was he talking about?
"So, I have decided that we will be using live models instead of boring pictures. And I will be the first model"
He stripped entirely and revealed his gorgeous cock. "And now I need a volunteer."