Baruk the Cursed by Cara Wylde

When the orcs invaded the human dimension, no one could stop them. War raged for years, and now the monstrous beasts have agreed to peace on two conditions: one, the human scientists must rebuild the machine that brought them into this world; and two, they must be provided with fertile brides to bear them orc babies.
Jenna Cole is done with her family, and the world of humans in general. She might as well become what they all say she is – an orc tribute. She doesn’t expect the brutish orcs to welcome her with open arms, especially after she’s had to escape from a horde once, but maybe she’ll have better luck this time. And as beastly as they are, if a captain chooses her as his bride, maybe he won’t betray her. Like her entire family did. Maybe he won’t shun her, maybe he’ll see her for who she really is. In the end, that’s all she wants: to be seen.
Baruk the Cursed needs a nanny for his twins. His horde has no females, and the only woman he’s ever loved is gone. When he meets Jenna at the institute for orc brides, he thinks she looks motherly enough. The twins are suffering after their mother’s loss, and the blond, curvy human might just be able to soothe them. As for him… Baruk doesn’t need anyone. Not anymore. They call him the Cursed because he’s always had bad luck. He took a bride once, and now she is no more. He won’t risk having his heart torn from his chest a second time.

Author’s Note: This is a full, standalone novel with a happily-ever-after. The books in the Orc Mates series can be read in any order.