Sorry for the delay - you might want to read the first part of this to work out who the characters are as there's no recap!
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Frank couldn't believe that his life could change so much. His sister had promised him so much, a life full of debauchery now that he was back under her control, but even then he never dreamed that everything she promised would actually come to pass.
Over the last four months, since she had convinced him to buy the old abandoned school house in the middle of nowhere, things had changed beyond all recognition. Thanks to the Ctholoid cum that he had eaten - mixed in with his food as he never wanted to take it from the source - he had lost a huge amount of weight, becoming lean and muscled; his hair had grown back; his face had smoothed and lost the signs of age; and his dick . . . Frank had always been ashamed of his small dick and his premature ejaculation but now he possessed almost a foot long cock and a pair of balls that produced enough cum to almost drown someone and he could fuck for as long as he wanted.
His sister, Janine, had changed also. Gone was the thin, bony woman with the hairy upper lip and in her place was left someone who looked as though she had walked off the set of a porn film. Her hair had become thick and lustrous, a dark blonde mane that fell to just above her waist; her legs were smooth and toned; her ass was round and pert; her facial features had softened, her lips becoming fuller; and her breasts had grown till they were each almost the size of her head. She was still herself, though, still the one in control of things, and made sure she reminded him of that.
The building had been done up and, a couple of months ago, had been re-opened as the Chambers Academy for Wayward Young Women, taking in six teenage girls from schools that were glad to be rid of them. The girls, belligerent and troubled at first, were unknowingly fed food liberally mixed with the cum from the Ctholoid in the basement. As a result, not only had their behaviour changed, but, like Janine, so had their bodies. Each of them had turned into a schoolboys wet dream - long legs, gorgeous looks and really big tits.
As the supposed head of the private school, Frank wasn't expected to teach the girls anything; his sister took those duties on board, and his role was mostly for show. After they had first opened, various officials had come to inspect the place and Frank had been the one to show them round. Now, though, they were mostly left alone, something which suited both Frank and Janine immensely. The lessons, too, had become less formal as the girls had altered in both mind and body, becoming compliant and willing participants for Janine's real lessons. His sister had them act out plays that she had written, each successive one featuring more and more sex. While the girls would not have considered even kissing each other when they first arrived, as the weeks and months went on, they were more than eager to act out Janine's debauched lesbian fantasies. Frank had his pick of them as well - at least one of the girls would visit his room in the evening every night, sometimes two or three at a time. Those that were left in the dorm room would eagerly indulge each other's passions.
Janine spent most of the nights in the basement, harvesting the cum from the Ctholoid, keeping some for herself and placing the rest in jars to spread amongst the food. She had allowed him to watch on more than one occasion as she had been fucked in every hole by the thing's cock-like tentacles; true to her word, as the thing had grown it had sprouted more and bigger dicks until it now had five. The first time he had been brave enough to jerk off while watching her getting fucked by the thing, she had smiled at him, looking longingly at his new, big dick while the Ctholoid plunged its own cocks deep into her pussy and ass at the same time. No matter their changes, however, she still wouldn't let him fuck her.
He sat behind his desk in his office, glancing through the paperwork that still had to get done despite the bizarre nature of his new life: bills had to be paid, however his world had changed.
The knock at his door made him look up, though, and he smiled as one of the students entered.
"Please, sir, I've been asked by Miss Chambers to ask you to join her at the basement." the girl said. He grinned as he looked at her, the perfect image of the slutty schoolgirl. None of the girls had wanted to wear the uniforms when they had arrived but, after the first couple of weeks of unknowingly eating the Ctholoid cum, they had become more susceptible to Frank and Janine's wishes. Each of them now wore the same style outfit: short pleated skirt, ankle socks, and a blouse that struggled to contain their huge tits.
Over the last week, Janine had decided to introduce each of the girls to the Ctholoid and, despite their initial revulsion, due to the pheromones it produced and their strong libidos, each of them had gladly given themselves to it. Now, it was the turn of the last girl.
"Thank you, Maria." Frank said. He stood and walked over to her, slipping his arm around her waist and guiding her out of the office. She hugged him back and he could feel her big tits pushing against his chest. They walked along the corridor and down the stairs, past the single classroom and over to what had been the cloakroom. The other four girls had been asked to remain in their dorm room while the last of their band, Caroline, was introduced to the Ctholoid.
Janine stood outside the door to the basement with Caroline who was dressed in the same way as Maria. While she knew something was happening, she didn't look nervous; she and Janine were close together, the teenager running her hand up Janine's thigh, both of them turning to look at Frank and Maria.
"So what's happening?" Caroline asked.
"All the other girls have seen what you're about to." Janine said. "We asked them all to keep quiet until you'd all seen it, and you're the last one."
"You might be a bit scared at first," Maria told her. "But once you give it a moment, it's fantastic."
"Hush now." Frank said gently spanking her pert little ass. "You'll spoil the surprise."
"Sorry, sir." she said automatically.
Janine opened the basement door and turned the light on, revealing the dusty floor and the walls with the sigils still in place.
"There's nothing down there." Caroline said.
"Trust us." Janine said and took her hand, leading her down.
Frank and Maria followed, staying at the top of the stairs, watching the other two reach the bottom. As their feet touched the ground, the earth in the centre of the basement moved and surged, five tentacle cocks erupting and turning towards them as if looking at them.
"What the fuck is that?" Caroline shouted, holding on to Janine's arm and trying to hide behind her.
