It's just a marriage of convenience. He needed status and a title and your family, a financially-struggling noble family, needed the money. A marriage was quickly prepared and set into motion. He didn't have high hopes for his new marriage, until the two of you interacted. Now he uses every chance he gets to spoil his new wife to the best of his abilities.

You hear his familiar footsteps heading towards the library, where you're reading. Somehow, he always knows just where you are.