For the Love of the Gods by Rory L. Scott

Hades and Pluto. Husband and Wife.

The Underworld is inevitable. No matter your status as a human, everyone ends up there eventually. For two millennium, souls would pray for safe passage from House Hades or House Pluto. But when an unexpected birth forces the houses into competition, the already tense relationship between Lady Hades and Lord Pluto will come to a head.
Dominic wants revenge. Rose wants solace from Dominic’s prying eyes and thinly veiled contempt. When marriage between their two houses is the only option to keep the Upperworld from turning their decades-old anger toward them, they are forced together. The longer they spend in each other’s presence, the more unlikely achieving those goals become. As lies between the two of them and between the humans and gods themselves unravel, only one of them comes out victorious.