It was my first day on the job as a sex ed instructor, so I was a little nervous when they told me about the three Senior students I had to teach after school. They were mischievous babes who were often failing and skipping class. So it was my job to keep them up to date on this particular curriculum. Okay, calm down. I ordered as they gossiped with each other. We're gonna learn about, the male genitilia. As I expected, they all nodded and giggled. Throwing sly looks at each other. I went ahead and attempted to explain the functions of the penis. Much to my surprise, they all admitted to never seeing a penis before. I showed them a drawing in the textbook and a couple of babes cringed. I actually had to tell them what ejaculation was for. And what sperm looked like microscopically. The babes expressed that they really didn't know what I was talking about. So, I tried drawing a better version of the penis on the black board behind me. Again they were criticizing my demonstration method and suggested they see what a real penis looked like by me showing them mine. Just SHOW us. They said. Oh... no. No, I'm not gonna show you guys. Come ON! They persisted.Well, I guess I could show you... I gave in, as I unbuckled my belt. They all moved in for a closer look as I began to pull down my slacks, exposing my half-hard cock.