His Fated Mate by Eve Riley

The truth of the heart is written in the stars…

Conall Blair is the son of Gray Vale’s Alpha, but he’d rather be a thorn in the side of the neighboring Stoke Ridge pack. For him, peace and harmony are little better than death—in all aspects of life, even relationships.
Zoltan Valenta, heir of Stoke Ridge, is a man of duty who’s suddenly having doubts. Though his father has arranged his marriage to Fiona Blair, Zoltan can’t shake his fascination with her twin brother, Conall.
When the two men find themselves unwittingly pushed together, there’s no denying the heat between them. Against all rules, expectations and commitments, can they really just yield to the hand fate deals them?