The Mermaid Next Door

In the Midlife Mermaid series by J.R. Rain and H.P. Mallory, mermaids in Corsica are considered valuable breeding property until their mid-30s, leaving them at the mercy of mermen. At 40 and a widow, the protagonist finds herself targeted by her late husband's younger brother, Cullen, who insists on taking her as one of his wives. Determined to escape her fate, she flees to the human world, where she discovers that her siren's song fails to enchant one man, Sawyer Ray—who may hold the key to her survival against unseen threats.