American Squire by Sierra Simone

Former presidential aide Ryan Belvedere has been drifting in a fog of misery ever since his president was killed, but he reluctantly agrees to do a favor for a friend—fetching a rare book from a crumbling manor house in England. There he meets Sidney Blount—cold, sophisticated, Dominant—who’s at the same house to appraise the family art. It doesn’t take Sidney long to appraise Ryan too, and decide exactly what Ryan needs. Which just so happens to be the one thing Sidney wants to give…