Mine, Ours, Theirs

Linnea
My mother's new husband owns the roof over our heads, the doctors who keep her alive, and every debt we've ever carried. All it cost me was moving into Gullwick Hall, a crumbling estate on a fog-choked coast where the tide runs the wrong way and nobody will tell me why.
His sons are the real problem.
Dorian is cold, immaculate, and lethal when he's patient. He watches me like a tide watches a shoreline. Rafe is all storm and teeth, touching me like he's daring me to flinch. Emrys barely speaks, but he sees every lie I tell and still leaves flowers on my windowsill.
They're my stepbrothers on paper. We met three weeks ago. Nothing about what they want from me is brotherly.
Dorian
The Compact requires a bride for the sea. I was told to deliver her, not want her. But she walked into my house with her chin up and ink on her hands, and something old in my blood sat up and whispered mine. My brothers heard it too.
They think they can share her. I think I'll drown anyone who tries to take her.
Linnea isn't a sacrifice. She's the first person in three hundred years to read the Compact and find the loophole. But the sea doesn't bargain gently, and the men who love her are monsters who have never learned how to ask.
They'll have to learn. Or lose her to the water.
Heat level: high. Fully explicit scenes throughout, including multiple-partner intimacy. All characters are adults. No cheating; the central relationship resolves with a guaranteed HEA.
Content notes: possessive and obsessive behavior, supernatural peril, bloodshed, family betrayal, explicit sex.
Tropes: Reverse Harem | Monster Romance | Stepbrothers (met as adults) | Forced Proximity | Fated Mates | Possessive Heroes | Family Secrets | Slow Burn | Morally Grey Heroes