One of the girls has a question first.

One of the girls raises her hand, "How can you tell he's about orgasm?"

"Great question," Diana says, "Joe, why don't you show us what happens when you're about to climax."

The class is rapt with attention. You're getting close, so you start really whacking away at yourself. You glance over at Diana, and you can tell she's really enjoying this, even though she's looking at the chalkboard and pretending not to notice what's going on.

The cute blonde is watching intently, and you can see her biting her lip and struggling to stifle a smile as you pump yourself. You can't help but moan and groan as you get closer and closer, and you're sure you can see the girl's perfect breasts heaving in excitement as she watches you.

"Would anyone like to try and feel what's happening to Joe's penis?" Diana asks, apparently not wanting to miss the opportunity to provide a hands-on lesson for the class.

You watch as a girl in the front raises her hand. She's wearing a figure-hugging gray sweater and it's clear that she's not wearing a bra. You can see the curve of her breasts under the tight fabric, and you're getting even more excited.

The girl gets up and approaches you hesitantly. You're still jacking yourself off, but now you're at the point where you can't stop. She reaches out tentatively and touches your cock. It's a little awkward, because now you and she are both grasping your erect penis, but you manage.

"That's right, rub your hands up and down," Diana instructs her, "That's what Joe's doing."

The girl starts to rub your cock. She starts slowly at first, but then, as if she can't help herself, starts to rub it faster and faster. You're really into it now, pumping your cock furiously and the girl keeps pace. You stare at her breasts as she pumps you, and watch her nipples harden through her sweater.

You realize you're about to cum!

You hold on as long as you can, as the girl rubs you harder and faster. You look at Diana, she stares into your eyes for a long moment. It's all too much, and you can't hold back anymore. You feel a rush of pleasure and you let out a loud groan as your body spasms, spurting semen all over the girl's hands.

You try to catch your breath as the girl just stands there, looking at you with a mixture of embarrassment and curiosity. You feel a pang of guilt for cumming on her, but you look over at your friend Diana, who gives you an encouraging smile.

Most of the girls are looking at you with a mixture of shyness and curiosity, but the girl who was rubbing your cock gives you a little smile. You both blush a little.

"So, Joe. Did you enjoy that?" Diana asks, smiling mischievously.

"Yes... I really did," you answer.

"Do you think we could show the girls how to give a blowjob? I think they'd really like to see that.