Not gonna fit

Request: Can you do one where two old men from retirement homes, who know each other for a lifetime become husband and wife and are having much more fun now than in their retirement home?

"It's so big! It's not gonna fit! Ohhh!" Jason cried as he slowly lowered himself onto Brent's dick.
Jason was so horny and so wet, and Brent was so gentle. He was eased down onto the cock. Jason took small hitching breaths as he was filled, his body stretching to accommodate Brent's girth. He stared down past the perfect tits they'd had so much fun with recently, to the pussy he'd been tempted to try for the first time. He watched as Brent's huge new dick slowly disappeared inside him.
The two used to be old men who lived in the nearby retirement home until the Great Shift swapped them into the bodies of this young married couple. There had been a period of chaos and adjustment, especially for Jason who found himself transformed from an overweight guy in his mid-80s to a young blonde.
They felt bad for the young couple who were now stuck in their aged bodies, but what could they do? Besides, married life outside the retirement home was so much better. They'd been friends for years, but now they were friends with benefits.
Jason finally sunk all the way down, his body filled with a welcome kind of pressure. Fuck, he was so full, on the edge of pleasure and pain. And yet when he rose from the cock it left a strange emptiness inside him, sated only when he sank back down onto it once more.
The sight of his tiny body getting filled was enough to bring him to orgasm, and he clenched the cock tight inside him as little moans escaped his lips. The first of many.

Four friends accidentally discover that a mysterious remote control can transform them into duplicates of people on television in Remote Chance, available on Smashwords or Amazon or wherever ebooks are sold. Preview here.