Koyoi's passage tightened, gripping Elt's penis. Then it relaxed, constricted, relaxed, constricted. Her whole sex squirmed and convulsed. A single thrust had brought her to climax.
A monster girl's pleasure derived more from emotion than from physical acts. Having to set out for Zipangu without her beloved husband saddened Koyoi. At the same time, being alone with him fulfilled her desire to monopolize his affections. Then there was the satisfaction that came with his accept her from the bottom of his heart. That single insertion has set all of them off.
"Ooh... I'm sorry... darling..." Koyoi apologized, hanging her head. "I know I need to see to... of your needs, too... but I'm just... pleasuring myself..."
Both her thoughts and her face were slack with ecstasy.
"Don't be silly."
Elt hugged Koyoi gently, but firmly.
"You're my wife, Koyoi. I don't care about... things like that. I'm just glad... that we can... feel good together.
"Actually," he continued, "I'm the one... who has to apologize."
That surprised her. She stared at him, eyes wide.
"I've been wondering... if I'm really the best person to be your husband. I mean... we'd only just met... and there must be a better man for you... back in Zipangu..."
That was as far as Koyoi let him get before she stopped up his mouth with a kiss.
Ignoring his stifled protestations, she forced her tongue between his lips and made him swallow her saliva along with his words.
He put up a feeble resistance at first, but it soon melted in the face of pleasure.
Koyoi waited until she was sure of that before finally releasing his mouth.
"Please, don't say any more," she said with an unusually serious expression. "It may be true that I'm a fool for falling for you at first sight, darling; but!"
The sudden roughness of Koyoi's tone made Elt's shoulders tremble with surprise.
"I don't regret it. Being with you fills me with joy."
She began to thrust slowly back and forth. She continued embracing Elt; only her hips moved like broken clockwork.
"Aaah... When I do this... your cock churns... my dripping vixen cunt..."
She began grinding her hips in circular motions. Elt's rigid member pushed open her fleshy hole and ground against the entrance to her womb.
"Every day... Every day I wonder... if it's alright for me... to be this happy..."
Her expression softened. Her tongue lolled, trailing drool, but she did not care. She was focused solely on the movement of her hips.
Koyoi's face said that all she needed was pleasure. The sight of it made Elt's heart race. His own member was putting a look of heartfelt bliss on the face of the woman before him — his beloved wife. Nothing could do more to fulfill his sexual desires. The overflow of feeling trickled back down into his body as an urge to ejaculate.
"Darling, you've... mmm... gotten even... ah... bigger. You're about to cum... aren't you?" Koyoi panted happily.
She added vertical motion to her thrusts. She twisted her hips with each downward stoke, clenched her vagina, then raised them again.
"Ooh. That's..."
Elt grimaced as he endured the thrills of pleasure creeping through every inch of him.
The densely-packed folds of her vagina tickled the sensitive parts of his penis with each upward stroke. When she thrust down again, her cervix latched onto his tip like a suction cup, or like a gentle kiss.
Both their mouths hung loosely open. Their breath came in pants from deep in their throats.
"Koyoi...!"
He shot her an imploring look. A thrill of pleasure raced up her spine. The way his face looked just before climax always aroused an almost maternal love in her.
"Yes! Yes! Go ahead! Shoot you cum all the way inside me...!" Koyoi somehow managed to gasp.
She covered his lips with her own, wrapped her arms around his back, and squeezed his waist between her legs.
Their bodies were now completely motionless, but only to outside appearances. The pleats and muscles of Koyoi's vagina were moving even more and harder than before. Her hole contracted and relaxed from the base to the tip, moving almost like it was milking a cow's udder. Her fleshy pleats tickled all of his penis' most sensitive parts.
The muscles in Elt's face tightened. A muffled grunt escaped his stopped-up mouth. A moment later, his glans swelled and spewed forth all the semen that had built up in his testicles.
Tears gathered in Koyoi's eyes as she quivered with delight. His urethra and her cervix were pressed tight against each other. Every last drop of semen poured directly into her womb.
She panted and moaned as large tears rolled down her cheeks. She had reached such an extremity of joy that the cascade refused to stop.
Her breath coming in short gasps, she let her chin drop loosely on his shoulder.
"Haa, haa... You're still... cumming..."
Her arms hung limply by her feet.
Elt was gritting his teeth and writhing under the intense pleasure that accompanied his ejaculation. As an incubus, his ejaculation was incomparably longer and more voluminous than it had been as a human. He could now consciously experience ecstasy that would have made a human faint. And because Koyoi was now a monster, she could take enough semen to make her uterus swell up like a balloon without feeling any pain.
At last his orgasm finished. He let out the breath he had been holding in. His body went limp, but he soon put new strength into his arms and hugged Koyoi to him.
She squealed.
"Koyoi," he said, steadying his ragged breathing, "promise me just one thing."
"Yes?" She nodded hesitantly.
"Come back safe."
Koyoi's thoughts were still hazy from her recent orgasm. The words spread through her mind like a pinch of earth in water.
"I promise!"
A few seconds later, grinning from ear to ear, she loudly proclaimed:
"I promise to return home in good health! I, I plan to bring my sister and her fiance with me, so when we get back, I'll introduce you, and..."
Smiling, the pair discussed their plans for the future.
The black sun of the monster realm neared the horizon. The evening sky illuminated the land. It would soon be time for Koyoi to depart.
Until then, she would rest a while in what she found the most relaxing place in the world, savoring every bit of the man she loved best in the world.