Looking for a story

Looking for a story i have read before. It is set in a future or alternate world where women have become free use unless they are wearing a marital ring. So to protect his best friend a guy gives his ring to his best friend and they end up falling in love.
Do any of you guys know this story?

Source: reddit.com/r/eroticliterature/comments/aky84g/looking_for_a_story