"Wagh!"
Squeeeeeze
"Nygeh--!"
Squeeeeeeeze
Every hard crunch from Citrine made Blake's little form sink deeper into layer upon layer of the malleable stomach wall. The panting and flexing of her cellular structure kept getting louder, and the outside world was harder to make out. He could only hang onto the barest thread of a psychic channel to communicate with her, with the lingering bit of his magical strength; and yet, he never felt closer to his orange crush. Between the rustle of her tank top, and the clang of her navel jewlery, he could barely raise his voice.
"S-stop..." He felt like coughing - and yet, he had no more lungs, Citrine doing all the breathing for him. "Any more, and I'll burn to a crisp..."
Citrine hugged him, between crunches. "I'm getting really hot, too, Blake! Ahhhhnn... Isn't it perfect?"
And she was right. Her entire chest area had a pleasant burn for her - and a scorching inferno for Blake. It lapped away at the meaty cells, sizzling under him. Burning her carbohydrates away... This effort seemed to shrink him more and more. She may have been toning her fat, but from his tiny perspective, the already-vast stomach seemed bigger each second; entirely unsurmountable!
"Stop! Any further and I'll..." Blake choked again, enduring the searing pain. "I'll be stuck in here forever! There'll be nothing left of me for you to burn up!"
Citrine gasped, stopping briefly. "R-r-really...?"
Blake tried to nod his head - only making the thinnest, scantest dot of a lump on her abdominal expanse jiggle. He basked in the cool breeze of stillness, feeling a sense of peace in this odd place on his new girlfriend world...
...Before said world let out an eruptive squeal. "That would be the best! Together forever with me... I'm sealing you in my inner dimension! Be by my side forever... In my front... My magically bound companion! J-just like the games!"
Blake could no longer muster an argument against the POUND and STRETCH and SQUEEZE of continued exercising. He'd only set her off further. His biomass grew weaker, smaller, tucked in tighter with every motion...
...And was, eventually, sealed into Citrine, with one terminal stretch of her legs and affirmative "glug". Any bit of fat Blake once contributed... gone. He didn't even have arms to pound on surrounding bits of tissue or meat. All of Blake, the magic student, the boyfriend... Gone. A little bit of energy for his girlfriend. He was only a spirit, hollowed out, haunting the now-marginally-less-plump bit of Citrine's abdomen...
"This is soooo fun... Let's do it some more!"
Further scrunches continued to torment him - throughout the day, the week, the month... He lost track of time. He lost track of everyone except the girl who swallowed him down. He'd only ever hear her voice again, listening to her talk about her interests. Only feel the touch of her shirts or her blanket. His only tastes of the fruits of life would be those she tossed into her stomach. His only motion, when she moved.
At the very least, she'd bring him as a character in her roleplaying campaigns sometimes. But every time the session ended, he'd return to his rightful place:
Eternally bound to the Elemental Plane of Citrine...