Throne of Secrets (Prince of Sin Book 2) by Kerri Maniscalco

A sinful prince. A determined reporter. A dangerous rivalry.
 
Gabriel Axton -the Prince of Gluttony, self-proclaimed rake of rakes - lives for indulgence. But when a hunt takes a deadly turn, he realises something is very wrong in his demon court. With the clock ticking, he must turn to the one person who can uncover the truth: a journalist he has spent a decade avoiding...
 
Adriana Saint Lucent has been on the hunt for years - if she could just report something damning about Gabriel Axton, she knows others would finally see the no-good demon as she does. But she never expected to turn up a rumour too terrifying to be believed. And soon Adriana's investigation leads her to the place she dreads most... Axton's infamous court.
 
To stop darkness from falling over their kingdom, Axton and Adriana will have to unite against an escalating danger. But with each holding tight to their own secrets, can they find the truth before it's too late? And what will they do with an equally troubling rumour: that they might not hate one another, after all?