"What the actual fuck!" Logan yelled, staggering back at the sight. Even though he'd seen his sister naked just moments ago, it was the view of someone who didn't live in the same house as him that made him infinitely aroused.
"Hehehe, don't be so frightful," the girl teased, going translucent as her body passed through the window without even a tinge of struggle in her face.
Her hair had been a free-flowing red, petite with moderately sized breasts and a decent ass. As to why she'd been revealing herself so much—and at his window, no less—Logan didn't know, but that didn't help the raging boner hiding in his gown.
"My, aren't you riled up?" she joked once again, lowering herself from her float to look down at the huge bulge protruding from his bathroom gown. Logan's dick almost stuck out, forcing him to push it to the side with his hand.
"What the hell are you doing in my room!?!" he yelled, darting to the opposite side of his room where his bed was as fast as his large body would allow.
"You don't know what I am? Maybe this will help."
As soon as she spoke, her skin begun to contort, pulling towards singular points as something dug its way from inside. At first, it was two sides of her scalp—blood trickling down as horns released themselves violently. As quickly as they'd escaped, though, the skin healed, closing in on itself to wrap around the matte black, hard material.
Moments after, her back also began to suffer the same effects, giving way to two thin, black bony protrusions to jut out from where her shoulder blades were. It didn't stop at that, though—their ends drawing inwards like that of a sideways 'L'. Additional bone dipped down to cover the space between her back and the ends of her newly formed bone, followed by purple flesh to connect the empty space occupying the bone, eventually settling into a thin film that functioned as wings.
"A succubus..." Logan murmured, appalled at the beauty of her form. Her fingers also began to elongate, the nails turning jagged, but all it took was one casual glance from her for their edges to turn more blunt.
"In the flesh!" she laughed, taking her hands to her hips.
In his world, there were humans that resided in the living world, and then there were creatures of the abyss. Spiritual beings, who all existed as the personification of mana. While humans could only manipulate the atmospheric mana—energy that fuels magic—spiritual beings lived and breathed it. Hell, their forms were contingent on mana.
With a single breath, she leaped from where she stood directly to Logan, violently dragging him to his bed. It all happened faster than he could react, the sudden movement knocking the air from his lungs. "Kuhhhh... how...?"
"How what?" She grabbed his wrists, pushing them down over his head. He'd been fully emasculated by her domineering presence. "Ah, you mean how am I roaming around the human world without getting hunted by those spirit hunters? That's not for you to know."
He struggled to resist her grip, but her hands were unmoving. She held such strength within her that for just a second, it'd seemed like a giant mountain had found its place on top of him.
"What are you going to do..." he gasped, begging for air as her weight pressed down on him.
"I should ask you the same thing. I mean, just look at you," she giggled, moving her ass just a hair back. His dick had been fully unsheathed from his gown, unnaturally pressing up against her butt.
Its tip ejected a drop of pre-cum, wetting her thin, black leggings. As she moved, the girth of his cock rubbed between her buttocks, beginning to get covered in its bulk. He couldn't help but shudder at the pleasure, biting down on his bottom lip aggressively.
"Usually, they say fat guys tend to have small cocks, but I suppose you're an exception to that rule." Her playfulness ramped up tenfold, her tight grip on his wrists releasing as she instead gripped onto Logan's chest, rubbing her butt even further down, even beginning to brush his dick with her crotch.
"Hold on!" Logan roared, finished with her banter. Mustering all the strength that his body would allow, he shoved her off him, turning her to his covers as he instead flipped the script to mount her from the top.
"My, look at you—being bold. What, you don't want to fuck?" She seductively picked at her lip with her index finger.
"No... I just... there's a girl I like, and I want to save myself for her. Plus, I don't want my first time to be like this..."
For a minute, silence.
"Hahaha, are you serious!" She leaned her head up a few inches, peering deeply into Logan's eyes. "Look, sex isn't something to be sanctified. It is a natural thing people do; either for reproduction, fun, or survival."
"Survival?"
She exhaled, rolling her eyes. "I know you're smart, kid. Stop playing dumb."
Logan understood what she was talking about. Succubi—and all spiritual beings—leech off of 'life force' to survive, something that only humans contain in their bodies. In the case of Succubi, they could only retrieve this life force through semen ingestion.
"But why me?" he asked, losing his attention on what she was doing.
"You really don't know? I could sense you from across the city—all that mana pent up inside of you. You were exuding such life energy that I just had to snag you—grggghhhggh!" Warm flesh wrapped around his dick that had been standing up, almost poking her in the face.
"Hooohhohhhh..." he groaned, looking to the ceiling at the pleasure.
She didn't stop at just taking his dick with her mouth—she began sucking her cheeks in, creating suction.
The wetness from her suctioning combined with the pressure of her throat was enough for Logan's mind to go white. It was like a nice, warm blanket made of soft material were embracing his penis, and it didn't help that she began to move.
Swallowing him inch by inch, Logan's dick convulsed uncontrollably, finding pleasure in her throat as it flexed. She let out a guttural gag, spit bubbling on her chin as she took a moment to acclimate to his length and girth.
His chest caved inward with an intense, breathy gasp. The air grew more humid, his cheeks turning blush from the intense stimulation. Never before had he felt this good, but she wasn't stopping.
Each time she took his cock to the base, she would use the back of her tongue to twist around and play with his shaft, even going so far as to lick his balls.
"I-I'm going to cum..." he breathed, gripping onto the sheets with his hands. "I... I... I..."
The world went black as his eyes rolled into his head, fireworks blasting all across his vision as his dick plopped out from her mouth, clenching repeatedly as streams of white released from his urethra.