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. They asked questions like what side my cock hung most often, how it got hard.I started tugging on my shaft in order to get the blood rushing so I could show them what a hard cock looked like. "Can I see what it feels like!?" The blonde asked. She reached out and started playing with it, very interested and attentive. Another student came in to feel for herself. While they were oohng and awwing, I closed my eyes and enjoyed their fingers as they played with my hard dick. All three of them began taking turns tasting my cock, licking my balls and jerking me off. I moaned and let them know what a good job they were doing. They were curious to see how big my cock had grown, so one of the students grabbed a ruler and brought it right to my groin."Seven inches!!!" They exclaimed before getting back to work on my stiff dick. They milked it so good, it was hard for me to believe they'd never done this sort of thing before. I trembled and braced myself as I felt the stirrings of an explosion occurring. "Oh my goodness ladies... I'm going to cum!" My load shot out f0rcefully, all over their hands and chests. The babes were so pleased with what they had learned that they grinned and giggled with each other. I very was satisfied that the students had all understood the day's lesson. "Well ladies... I can tell you that you all get A's today." "YAAAAAY!" They unanimously shouted.