The one called Tricia lowered herself naked into the water, letting the two blonde-haired girls tie her to stakes spread out in the water. She sank to her knees, her breasts floating in the water, everything but her head submerged.
"We are reluctant to leave," the one called Tricia said.
She was different than her friends, shorter dark hair, a smaller more petite frame that contrasted with the taller, lankier blondes.
"It is the agreed-upon time," the one called Taylor said.
"Even so..." the one called Tricia said.
"We must practice speaking as them," the one called Tayna said. "This method requires a greater sociological understanding."
"To blend in, we must be better," the one called Taylor said.
From between her legs, two oblong shapes pistoned themselves inside Tricia's naked body. The inserted tentacle creatures were barely visible, their flared bases keeping them from disappearing entirely inside the brunette girl's used pussy and anus. Had they wished, the creatures could have changed their appearance to shrink further inside of her.
Instead, they filled her completely, using their bases like a tail, gyrating inside the poor girl as they caused climax after climax brought out by hours of hidden torment. They moved inside her, spilling their endless seed repeatedly, soaking the poor girl's panties as she continued her daily life...
Completely under their control.
The two dildo shaped things let out one last simultaneous orgasm, unleashing a torrent of semen inside of the girl, then quickly withdrew. Their camouflage disguised them perfectly, and underneath the clear, still water, they looked almost like small sharks as they swam away, replaced by a growing school of monsters swimming towards her exposed sex.
Only then could Tricia, truly Tricia, really scream.
"What the fuck are you doing to me?! Please, please stop..." She sobbed. "I'll do anything, I'll let you do anything..."
"This is a distinct disadvantage," the one called Taylor said. "We are vulnerable during these transitions."
She kept screaming, pleading, crying as the small thirty centimeter long sharks swam closer to her, each of them competing to reach her open orifices first. She struggled against the restraints, trying to pull the stakes free from the muddy soil, only for the chains to keep in her place. The nose of one of them brushed against her thighs, the panic causing her to kick and flail until her head was underwater.
"We are adapting the next generation," the one called Tanya replied in the same toneless voice. "But it will take time if we do not wish to draw the attention of the others."
She could see them now, different without the light reflecting back. Underneath, staring between her own legs, Tricia saw the things, like the bulbous and curved appendage of a primordial crustacean. There seemed to be thousands, in different shapes and sizes, most a curved foot or two, twisting awkwardly in strange patterns to swim closer, all competing to use her cunt.
"We must remain hidden," the one called Taylor said. "The others are much stronger."
A curled spongy head teased Trishia's lips, tensing her up for everything to begin again. She closed her eyes, ready to lose herself again as the monsters walked around in her body, controlling everything as she watched behind someone else's eyes, constantly conscious of the two alien cocks filling her abdomen.