Pulled By the Tail by Nancey Cummings

Wife Wanted: Aristocrat Needs an Heir. Fertile Females Only.
A clerical error matched Georgia to the wrong alien. It’ll take months to get their marriage annulled, so she’s stuck in a grand house that’s falling down on a backwater planet with a massive brute of an alien who likes books more than people. But the more time she spends with Talen, the more she questions if their marriage was a mistake after all.

All Talen has in the universe is his family. When his brother’s latest scheme delivers a human female to his door, technically his wife, he refuses to turn her away. She’s part of his pride now and he knows that her luscious form and biting wit is vital to his future. He’ll win her heart and convince her that nothing about the heat between them is a mistake.