The ground floor

The human on the lowest floor should be the easiest to find. The slime searched for a way in. The simplest way in would be through the door in front of it. However, it was shut, and the slime did not want to attempt to open it, lest the human inside realize its intrusion. Thankfully, it was made of liquid.

Coming up to the door, the slime’s humanoid form began to break down, green goo seeping into a puddle that moved on its own between the cracks in the wooden surface. Carefully and with only a small amount of effort, it seeped indoors.

The last of the infiltrator puddled onto the tiled floor, and rebuilt itself into its featureless humanoid shape. Now inside, the slime began searching the area. The room was mostly dark, save for a light and an electronic display in an area with furniture. It appeared that there was some athletic contest on the screen. Much to its satisfaction, the slime found what it was looking for: a human, most likely male, sitting on a couch. He was not looking at the large screen, instead looking at a smaller mobile device and stroking something in his lap with one hand.

“This would be an easy possession.” the slime thought. Being as silent as possible, it reliquefied and kept close to the ground, sliding behind the man. It could hear him speak, but it seemed it was only in reaction to whatever was happening on his device. The slime focused itself once again, reforming not as its humanoid self, but as one long, solid tendril, twirling up into the air until it was directly over the human.

That was when he noticed it. Looking up, his eyes went wide and he muttered something in surprise. But it was too late for him. The gooey tendril dove downwards, directly onto his face. It immediately went for his orifices, shooting into his nose and mouth. Silencing him was its first priority. As more and more of it flooded into him, the slime began to seize control of his body.

This was the strange limbo period the slime always enjoyed, when it could feel its senses and that of its host merge. Out of some kind of fog, it could begin to hear the sound of itself slurping down his throat, see itself trickling into his body out of his eyes. All resistance from him ceased, and the as the last of the alien made its way into his mouth, Ethan smiled.

The newly possessed man swallowed the last of his possessor, remarking that it somehow tasted very good. “Ah, back in another meatsack.” Ethan sighed. He stretched out his limbs, feeling the musculature he now controlled. His mind was flooded with not just information—about his work in the military, which was useful to the infiltrator—but also his emotions, the adrenaline that was still coursing through his veins. But that wasn’t all. There was something else, something the slime had experienced only once before.

Arousal.

Ethan looked down and grabbed what he now recognized as his dick. It came to life in his hand, feeling its warm, throbbing length. He furrowed his brow slightly in curiosity, trying to replicate what he was doing before a hunk of green goo **** its way down his throat. He was pleasantly surprised by how good it felt, watching his cock grow even bigger as he stroked himself. But that wasn’t all he was doing, was it?

Ethan then glanced down at his smartphone. On the screen was an image that made him well and truly hard again. It was a picture of a nude woman laying on her bed, legs opened wide. She was taking the photo with one hand, while the other was used to spread her labia wide with another. The blonde woman was giving a knowing wink as she did so. Ethan recognized this girl who had sent this nude to him. It was Casey, the girl he’d been fucking behind his wife’s back for the last five months. They were in the same unit together, which is why he didn’t even need to leave base to cheat on Tracy.

The possessed man started jerking off again, grinning as he remembered all the crazy sex the two had. He felt his arousal build even higher as he remembered pulling off her uniform, watching the crazy look in her eyes as she sucked him off in the motor pool late at night. He remembered pounding her ass, pulling her hair as she screamed out his name—

Ethan grunted in surprise, his abdominal muscles clenching as he felt himself start to orgasm. Ropes of bright green slime erupted from his cock, arcing high into the air before splattering on his chest. He gasped and continued to stroke, riding his climax out to the very end. When all was said and done, the possessed guy caught his breath and smiled dumbly. “That was fucking awesome.” He laughed.

The military man looked down at his stolen body, wiping up the green slime he had just cum out and drinking it back down off his hand. Man, his alien goo tasted good. And jerking off like that felt amazing. He had to get more of it. 'Ethan' stuffed his cock back into his pants and thought for a minute. Maybe this would be a good mission, both for the Empire and for him…