Story where a muscular girl forcibly feminizes a average man

[Discardo]

So I'm looking for a story where a muscular woman feminizes a normal/ very masculine man who had no prior feminine tendencies/ curiosities. Or a story where as the man becomes more feminized ( and maybe loses strength) she gains muscle/ gets more masculine. I'm especially looking for stories where magic plays little to no part and the feminization/ possible female muscle growth takes places through natural means. But feel free to share magical stories as well.