Introduce Alex to her new self

"Command me," Stacy spoke, but deep in her mind, she knew there was no need for that anymore. She and the creatures within her were now one and the same. Stacy as she once knew herself was gone forever, replaced with alien parasites transforming her body and using her mind to imitate her as they continued to spread further into others.

Speaking of whom, Alex was just now waking up and was briefly surprised to see two very large breasts on her chest. The creature in her brain quickly suppressed that surprise as it rewrote Alex's memories. Any previous knowledge of being "male" was altered and erased, to be filled instead with feminine thoughts and lesbian desires. Alex looked to Stacy and smiled as she opened her mouth, exposing a rapidly-elongating tongue much like Stacy's own. Getting the hint, Stacy opened her own mouth and let her tongue snake towards Alex's. The two members began to coil and climb on each other in a cruel parody of a candy cane. The tips of their intertwined tongues opened and locked onto each other, allowing both of them to share in the yummy nectar that was now pumping out of them.

Stacy grunted as she felt squirming within her giant breasts. The nipples began to distend outward as mouth-like suckers grew on their tips, latching onto Alex's breasts and licking the tips with internal tongues. The worms had reproduced and merged with her nipples now as well. As to Alex, her freshly-grown pussy was starting to twitch unnaturally, as if it too had become some kind of mouth. In a way it had, as it almost literally bit down on Stacy's penis and sucked with inhuman might. More of the worms were merging with their bodies and reshaping their flesh to better accommodate their mission.

Spread...

Spread. It was the only thing the creatures that were once Stacy and Alex knew now. They were the first, the progenitors of a new superior species. What little remained of their old selves could feel themselves blacking out forever, but even as they did so, they felt no fear... or any emotion thereof. The worms comforted them in their last moments, telling them that this was good, that letting it happen was the best thing they could ever do. And they accepted it.

Stacy and Alex fully disengaged from each other, though their hands never left each others's bodies as they continued to caress their wonderful, fleshy curves.

"I am Stacy," one spoke.

"And I am Alex," the other replied.

It was complete. Hosts and parasites were now one.