Chapter 1

“Today class we are going to discuss the role of dominance in regular sexual relationships. As some of you may know, I am highly submissive and Sarah here has recently switched to become a Domme.”

The 25 boys and girls choosing to stay behind after school for an extra Sex Ed lesson went very quiet, watching as Sarah carefully undid Cat’s blouse buttons to expose two tightly bound breasts.

“Oh shit, they are really going to do it,” observed one girl, releasing her boyfriend’s cock from his trousers.

Sarah landed the first slap clean across both hardening nipples as her teacher tried desperately to avoid embarrassing herself by cumming in front of the class.

Nobody quite knows when the theoretical discussion descended into a proper orgy but was definitely in full swing by the time the female PE teacher, Zoe, caught Sarah demonstrating the use of different strap-on techniques for fucking boys and girls.

Zoe is 26, 5 foot 6”, with shortish brown hair, busty, wearing tight shorts showing a gorgeous camel toe and a tight polo top just failing to hide a fabulous pair of heavy 36DD tits.

What the year-9 group didn’t realise was that Zoe was also training as a sex therapist until she asked them all to complete a junior version of the bdsmtest.org questionnaire and send their scores to the interactive whiteboard.

Unsurprisingly Sarah came out as the only female dominant, but she was delighted to see that their teacher Cat and several of the boys scored themselves as highly submissive.

She picked out one for a severe arse fucking as the others crowded around, waiting their turn, while Zoe made notes for her thesis on the sex lives of typical 14-year-olds in Andover.

Statistically, 96% of the girls and all of the boys admitted to losing their virginity by the age of 12 and on average had had at least 4 sexual partners by age 14.

Perhaps the biggest surprise was the distribution of bi-sexuality with the girls outnumbering the boys 5 to 1.

The openly lesbian couple spent most of the time checking out their next conquests from the few remaining girls who were currently unattached.

Seeing how much cum the supposedly straight boy Mikey produced onto Sarah’s tits when she fucked him up the arse in a forward cowgirl position, Zoe hatched a plan to help her older sister, Tanya and her useless brother-in-law.

His sperm count was so low as to be unmeasurable and the expensive IVF was still failing to give them the baby they so desperately craved.

Unlike Zoe, Tanya was completely straight and fairly repressed sexually, marrying far too young to understand or experience much of what turned Zoe on.

All the online articles insisted on a minimum age of 18 for sperm donation but seemed much more concerned with how many females a donor could assist, rather than the actual method of delivery.

Some mentioned Natural Insemination in passing, but none went into any detail, although it is obviously far more pleasurable for the donor and recipient.

“Right class, now pay attention,” said Zoe, licking the end of a small pink device, “who knows what this is?”

“A thermometer, miss”, suggested one bright girl, removing a boy’s hand from between her legs.

“Correct, Mary. It’s a regular basal thermometer. It measures your core body temperature. You can use it orally, but it’s much more accurate in the other orifices.”

Now she had their attention, running her tongue along its length, “I like to lubricate it before insertion and then clean it up after use. Who wants to try it?”

“Me first,” demanded Sarah, ripping off her panties and holding her lips apart.

“Good girl,” breathed Zoe, sliding in the thermometer until only the display was visible while gently massaging Sarah’s hard clit.

“Once the reading is steady, we can try the other place, just for fun.”

Zoe withdrew the device, sucked off the tasty juices then licked Sarah’s butt hole to ensure a well lubricated entry.

Several boys and girls smiled at Sarah’s look of delight as the special basal thermometer tickled her sphincter on the way in.

Zoe explained that provided you carefully measured the basal temperature in the same orifice every morning, the small rise indicated your Most Fertile Day, when an egg is released. So you should definitely desist from unprotected vaginal sex that day to avoid an unwanted teenage pregnancy.

If on the other hand, like my sister, you are desperate to conceive, then this is the best time to fuck like crazy.

“But remember sperm can last for up to five days inside the vagina, so the MFD stretches back for those five days when those little swimmers could still fertilise an egg if allowed to stay.”

Zoe pulled up the temperature graphs for herself and Tanya on the white board. Both showed the same regular pattern, perfectly aligned to the full moon.

“Are you witches?” laughed Sarah, pulling off Zoe’s shorts for a closer inspection.

“Cheeky mare! We just live together. I moved in 6 months ago to ‘help’ them conceive.”

The identical twins looked up from their intense finger fucking, “isn’t that incest?”

Zoe just smiled and changed the subject, “now class, remember that at 14 you are allowed to have sex in a story, but not in real life until you are 16. Also no pornography until 18, so don’t post any videos you make.”