Listen closely

All of the students listened to what he was saying, he pointed to his balls and told us that they were testicles, then to the head of his penis where he explained what foreskin is and why he doesn't have it. I looked over to Jeff to see what he thought but was utterly surprised to see his own cock outside of his fly. He was stroking it slowly. Did he get off on dudes? Was he gay?
"What the fuck are you doing?!" I whispered to him
Instead of being shocked that I saw, he seemed excited,
"I'm imagining you're up there instead of him" he smiled.
I was struck by the comment, so he had noticed me! He did want sleep with me! I stopped being shocked and just said, keep it up. He kept stroking his long cock while Mr. Adams was speaking and Jeff occasionally look at me to which I'd reply by biting my lower lip. Jeff was seriously making me horny!