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.