Rainse: Starlight Mermen #3 (Intergalactic Dating Agency). Starlight Alien Mail Order Brides, #9

A shipwrecked scientist. An alien who's given up on love. A bond neither of them can deny. Verity's life ends the moment a whale capsizes her boat. Adrift in the endless ocean, she's accepted her fate-until strong arms pull her from the waves. Her rescuer isn't human-he's an alien merman, covered in living kelp, breathing underwater, and looking at her like she's a miracle. Rainse has spent his life believing he doesn't deserve a mate.
Cast aside by his people and stranded on Earth, he's watched his brothers find happiness while jealousy eats him alive. Then he hears Verity's voice through the water, and everything changes. She's his-the bond proves it. But the dating agency that brought him here has rules about humans, consent, and proof. So Rainse breaks them all. He takes her to a deserted island. Tends her wounds. Feeds her by firelight.
And slowly, carefully, shows her what it means to be chosen by someone who would drown the world to keep her safe. Verity should run. She should demand rescue. But the scientist in her wants to understand this impossible connection-this pull that defies biology. And the woman in her? She's already falling for the alien who saved her life and asks for nothing but the chance to prove he's worthy of hers.
Perfect for fans of Ruby Dixon and Tiffany Roberts, this spicy sci-fi romance features fated mates, forced proximity, a grumpy alien warrior with a soft heart, touch-her-and-die devotion, and slow-burn heat hot enough to make the ocean boil.