My Kind of Sin by Trisha Linde

Over 250 years ago, Ulysses was born a sin-eater. Some would say it is a distinguished role, one chosen by the gods, to help humans unburden their souls and cross into the underworld, though all it has brought Uly is a life filled with shame and discrimination. He’s tired, ready to spend the last of his years in a mortal retirement. That is until a burly Irish god corners him in an alley with the promise of a mystery to solve… and maybe something more.

Ruadan hasn’t always been an immortal god, but with his rebirth, he was gifted the ability to shapeshift, with the expectation that he would use this ability to spy for the gods. Spying for gods, however, doesn’t pay the bills, which is how he finds himself working as a PI in Valleywood. When he allies himself with the prime suspect in a crime spree, an irresistibly untrusting sin-eater, he finds the lines between suspect and fated mate blurring faster than he can resist.