A Warlock Called Jacob by Michelle Frost

Jacob’s always been a dutiful son. His new mate is anything but.
Co-leading the Saint Coven with his twin sister is the legacy Jake was born into. He takes all his responsibilities seriously, especially his new Council appointed mate.
Cane is the mayor’s son. In a last ditch effort to put him on the straight and narrow, the mayor asked he be mated to the most mature and upstanding paranormal possible.
Jake is a strong leader, but Cane’s rebellious streak and the explosive chemistry between them might tempt him to the wild side.