It’s not a central part of the story, but off to the sides of Dark Souls 3 the player could get hitched. By default you’d be paired with an NPC of the opposite gender, but this mod for the PC version of the game by Matt Gruen flips all that.
Here’s the official description:
In this mod, take a romantic trip to Anor Londo to get summoned into your same-sex sweetheart’s world and slay the sludge monster that ruined their life. Or if longterm commitment is more your thing, head down to cozy Darkmoon Tomb and “marry” your beloved instead.
This mod makes Anri male if the player character is male and female if the player character is female. To do it the other way around, just play the base game.
Pretty simple! The only caution is that you should only use this offline, and if you use it and then want to play online, you need to delete all saves made, otherwise DS3 will detect the tampering and may ban you.
Here’s some footage of the mod—released in time to celebrate pride month—in action.