They were naked in a white room.
She held his erection and rubbed the tip in the moisture seeping from her, then paused and savoured the moment. She heard him groan in anticipation but held him firmly at her opening for a delicious moment longer.
Then, summoning all her strength, she took him into her.
First the velvet soft tip of his cockhead slipped past her swollen labia; then the fat rigidity of the shaft. He gasped.
Then, with a grunt, she opened her sex and sucked with her womb. He collapsed as she welled around him. First his erection, then the rest of his body shrank and disappeared with small slurping sounds, into her loins.
She whimpered softly at the exertion and the pain as she stretched around him. Beads of sweat formed a line along her brow. Panting for a moment, she allowed herself the pleasure of listening to his thoughts. She smiled as his surprise and then fear threatened to overcome his lust. Another squeeze with the muscles of her vagina forced the remaining protoplasm from his shrunken frame into his penis, now red and shapeless within her. The fears subsided as he transmuted into a state of primal flesh and lust.
Her breathing returned to normal and she stood up. She felt swollen and heavy, but she loved this moment. Her head reeled as he pulsed within her guts. His lust made her dizzy. For a moment, she thought she might fall.
An orgasm rippled up and down her vagina before spilling outward and engulfing first her spine and then her soul. She felt his orgasm building but he had ceased to have any functional organs, so his ejaculation, when it came was reduced to a violent pulsation of the meat imprisoned within her sex. Unable to obtain release, he settled into that blissful state that the tantric sages strive a lifetime to achieve. He throbbed slowly, gently, in the warm sea that was her womb.
She found herself standing, naked in the white room.
She was exhausted but the painful feelings of emptiness and hunger were gone. In the mirror, her reflection glowed, her skin tight and creamy pink. He was still large enough within her to cause a swelling of her lower abdomen above her pubic mound that marred the otherwise flat curve of her belly, but that would pass over the next few hours.
The room reeked of her; a pungent mixture of lust and sweat. She opened the blinds and looked out over the city. The rain had stopped and the streets below her pulsed, clean and wet, as if in rhythm with the shrinking flesh within her.