Futanari Adventure: Complete First Arc. Futanari Adventures, #5.5

Lacie never planned on becoming the talk of a goblin lair, acquiring a mysterious artifact, or growing something she definitely wasn't born with. She especially never planned on an elf. This complete first arc collects the full story of Lacie and Merina, from their first night sharing a room at a roadside inn to their wedding, their honeymoon, and everything gloriously explicit in between. It starts with a copper cup and one very ill-advised drink.
It ends with two women who've rebuilt their lives, their bodies, and their future entirely on their own terms. In between: dungeon adventures, a magic artifact that's rewriting the anatomy of an entire city, a court case nobody expected to survive, a transformation neither of them planned for, and a relationship that grew from cautious strangers into something neither had ever let themselves want before.