I was heading back to the Boys' School, accompanied by my sexy young assistant, Lyn. After her last visit there as my demonstration model, she was not being deprived of a second encounter with the class of horny teen boys, even though I had warned her that I had much more in mind for her this time.

Still not yet seventeen, she was again clad in school cardigan, blouse, school tie and skirt, although on this occasion she seemed to be wearing black stockings with a white suspender belt. The boys would love seeing her in that.

"Why the stockings and suspenders, sexy darling?" I asked, "got tired of socks?"

"No, Marie," she admitted demurely, "I saw the reaction you got from the boys last time, when they saw you in your stockings and suspenders." 

I smiled, flattered at the compliment.

"I am sure the boys will adore seeing you in them," I told her, "especially if you are wearing nothing else."

She wriggled delightfully at the thought.

"So you intend to let me be a plaything for them?" she asked, "like last time?"

"Not a plaything, a demonstration model," I corrected her, "but similar, yes. Any problem with that?"

"No, Mistress," she conceded, "anything you wish."

I patted her thigh, feeling her squirm briefly against my hand. When we arrived at the school, my helpful former teacher, now Head Master, James, was waiting to greet us. As soon as I was out of the car, he had me in his embrace, hand cupping my behind and kissing me deeply, not needing to be invited this time.

My timid teacher seems to have overcome his timidity with me, I thought, then revised the thought when he greeted Lyn in the same sexy way.  It seemed James was feeling much more comfortable in his contacts with females since knowing me.

"Are you sure that you want to use the gym today?" James asked, "it seems unusual."

"I am an unusual teacher, James," I smiled, "have you not noticed that?"

He grinned, probably recalling my last lesson where he was coerced into giving me oral sex in front of the class. Once unpacked, and after a much needed drink, we were led into the Gym, and I smiled at the sight of all the equipment, all so suitable for sexy fun.

Thick climbing ropes hanging down, walls lined with wooden climbing bars, vaulting horse, parallel bars, pommel horse, even a retro wooden horse with padded top, and some sets of gymnastic rings. Once again, I changed into my sexy teacher outfit of black underwear and the short teacher's gown. The boys from our previous lesson came in, smiling as they saw Lyn and I waiting for them.

"Good afternoon, boys," I welcomed them, "as you can see, today we will be continuing your Sex Education lessons. Everyone okay with that?"

Broad grins and heads nodding gave me the answer.

"Lyn has agreed to help again," I continued, "so shall we begin? Let's start with undressing the girl, see how many of you remember the last lesson."

I pointed to one boy, beckoning him forward.

"Would you start with the cardigan, please," I asked.

He stood in front of Lyn, fumbling a little with the buttons, but still getting it off her.

"A volunteer for the blouse?" I queried.

All hands shot up and I chose one of them. Lyn was already starting to blush as he began undoing the buttons. She raised each wrist in turn for him to undo the cuffs, and he slipped the blouse from her. I saw she had done what I had asked, and wore a bra this time.

"Now one for an expert," I announced, "anyone ever undone a bra?"

Two hands went up, and I pointed to one of the boys. He started to turn Lyn around, but I stopped him.

"No, not from behind," I instructed, "from the front. You need to learn how to do it almost accidentally while kissing."

I turned Lyn and the boy, so her back was to the group.

"Now, kiss her," I told him, "and try to get it undone gently, so she hardly notices."

Lyn looked at me, her face fiery red, and I merely smiled at her and nodded. The boy had remembered the lesson on kissing, and he put an arm behind Lyn's neck, then pulled her gently into a kiss. Lyn knew what I expected and enthusiastically responded. I moved so the boy could see me, and nodded.

His hands went around Lyn, one on each side of the clasp. A gentle pulling together of the two sides, and I saw the bra come undone. Before he could remove it fully, I took hold of the bra, and refastened it.

"Anyone else want to try?" I asked.

Stupid question, as every hand went up.

"One at a time," I ordered, "and refasten it after you have managed to undo it."

Each boy took his turn at kissing my delectable assistant, while unclipping her bra. I knew how much Lyn could get turned on by kissing, and she was squirming slightly by the time the last boy had done. I removed the bra from the last boy's hand, leaving Lyn topless in front of the class. Her blush was even more pronounced.

"Now we have uncovered most of our demonstration model," I pointed out, "we can start the hands on part of the lesson."

This was greeted by broad grins from the class.

"Ah, a slight problem," I said, "I think I promised tickling as part of today's lesson, did I not?"

More smiles and nods from the group.

"In that case, we will need our girl immobilised," I went on, "so she cannot accidentally interfere with the lesson, due to involuntary reactions to being tickled." 

This met with all round approval, except maybe from Lyn, who was looking somewhat apprehensive. I took some items from my bag.

"If two of you could attach these cords to those two rings, you will need a step to reach them, I think," I mused, "and please make sure they are secure."

The boys worked smoothly, tying the ends of the cords to the rings hanging above us, and even dangling from them to make certain they were well tied. I moved Lyn to between the rings, which were higher than I could hope to reach. I took the loose ends of the cords, and attached one to each of Lyn's wrists, pulling her arms up and apart before securing them firmly. I looked at Lyn as if surprised.

"It seems our young friend still has clothing which needs removing," I told the boys, "you, William is it? Would you be so good?"

He needed no second invite, and in moments my sexy Lyn was stood in just brief panties, tie, and her stockings and suspender belt. "That will do for now," I decided, "Now, 'Tickling'. It needs doing carefully, as with most sex acts. You and you, come either side of Lyn. Now try to see where she is ticklish."

They gladly complied, running fingers over every inch of her, and noting which parts elicited giggling, squirming, or outright helpless laughter.

"Okay, which parts made her giggle, and which forced her to laugh out loud?" I asked the class.

"Please, Marie," one spoke up, "under the arms got giggling, also under her boobs. Real laughter came when they tried her ribs, and her feet."

"Very good," I praised. Two to hold her legs up, then take turns two at a time to tickle, each completed pair to take over holding her legs."

Lyn glared at me. I think she had thought I was going to do the tickling and just let the boys watch. Silly girl. The boys enjoyed making my girl squirm wildly, while she laughed uncontrollably for each pair of ticklers. By the time it was over she was standing on slightly wobbly legs, trembling and with tears of laughter running down her cheeks and onto those gorgeous tits.

I wiped away the tears with a wet wipe, then turned back to the boys.

"Can anyone remember what other topics I was going to cover in this lesson?" I asked, "anyone?"

"Please, Marie," a voice called, "teasing and oral sex."

"That's right," I commended. "Hmm, teasing and oral sex is going to be a little difficult with Lyn still wearing panties," I pointed out, "I had better remove them, Yes?"

Cheers of approval met this idea as Lyn blushed again. I slid the panties down, aware that my robe was gaping open, and had ridden up as I bent my knees, giving the lads a good view of me. I stood, twirling the panties on a finger. The boys were silent as they enjoyed the even better sight of Lyn in just tie, stockings and suspender belt.

"I think we can leave the stockings and tie," I told the boys, "she does look very sexy like that, doesn't she?"

Silent nods of agreement from all. I looked around and saw a low bench, perfect for what I wanted.

"Could two of you bring that balancing beam or low bench, whatever you call it? Bring it here just behind Lyn, please."

The beam or bench was only a few inches off the ground.

Once it was in place, I called, "Two helpers please?"

A brief rush and two of the lads were there.

"How are you with knots?" I asked, "could you tie the young lady's ankles to the ends of the bench?"

They both grinned, and set to, pulling Lyn's legs wide, and securing the ankles to the bench very effectively. The result of having legs apart pulled Lyn's arms higher, so she could not lower them by an inch.

"Okay, teasing first, gather around," I ordered, "the idea is to make her squirm and wriggle, even moan if you do it properly. Two at a time, anywhere except her pussy, and move on once you have her as I described. I don't want her coming accidentally."

I sat, happily watching as Lyn was teased and aroused by boy after boy. No matter how she wriggled, she was unable to avoid a single caress, a single stroke or pinch of her nipples or squeeze of her backside. It was soon clear that she was getting desperate for a climax. I let the last few boys carry on, as Lyn changed to whimpering and trying to make her cunt rub against someone or something.

A waste of time, I had made sure she was completely immobile. As the last boy finished, I stood in front of her. She looked at me with pleading eyes. I stroked a finger along her slit, feeling the wetness, and forcing more squirming from her.

"I wonder if I should take the next part myself," I whispered in her ear, "let you watch while the boys make me come for them."

Lyn looked at me in shocked horror. I smiled at her, stroking her cheek.

"Relax, my sexy slut," I murmured, "I was teasing you. Of course you are going to be their first experience of oral sex."

"All of them?" Lyn asked, half fearfully.

"Oh yes, all twenty of them," I smiled, "and if you can still stand unaided after they finish, I will make them repeat it."

Lyn looked at me, not quite certain that I was joking, but her nipples sprang out nicely, indicating her excitement.

"You all saw how I enjoyed oral sex last lesson," I pointed out to the boys, and ignoring their broad grins, "now it is your turn to see if you can make our young friend come for you."

The grins changed to wide smiles at this. I arranged them so they could all have a clear view, and knelt in front of Lyn, using my fingers to part her pussy lips, then stroking along her slit with my tongue, slowly flicking her clit and then teasing it until she was trembling.

I stopped at that point, leaving her glaring at me.

"Lyn is very wet, and ready to come," I told the boys, "and each climax will increase her sensitivity, so be gentle, but firm. Thomas, you first."

Thomas took his place between Lyn's legs, and started eating out my sexy protegee, showing he had paid attention during my demonstration. Due to her already heightened state of arousal, Lyn was soon coming for him, and he returned to his place with a satisfied smirk.

By then, the next boy was beginning, and as I had warned them, Lyn was more sensitive, and each of the class easily made her come. My poor helpless assistant was kept wriggling and screaming, again and again, until the last one had done, leaving her hanging by her wrists, legs quivering and pussy twitching.

"Last lesson," I reminded the boys, "one of you asked how the man could get enjoyment just by giving oral sex to the woman. Does anyone still need an answer to that question?"

Twenty broad smiles and shaken heads answered the query for me.

"Very good. Next lesson we get to something you will enjoy even more," I promised them, "and that is when the male receives oral sex from the female. Also we will be starting your education in lesbian sex, where two females enjoy each other. Their techniques may help you when you start serious relationships with girls."

"Will the two females be you and Lyn?" someone asked.

I looked at Lyn, getting a smile and a nod from her. "Lyn will very probably be taking part," I confirmed, "but we will have to wait and see, regarding the other."

This seemed to satisfy them, and I asked two of the taller boys to release Lyn's bonds, helping her to sit on the low bench, legs splayed wide and still smiling. Each boy bent to kiss her as they left the gym, and my totally sated young helper.