Barely Regal by E. Davies

A bratty boy prince needs: a firm but fair Daddy.

Prince Renford is a royal brat. Nineteen and last in line for the throne, Wren hates his made-up job: Commander of Roses. Good thing his long-time valet has a firm hand—if only Wren could tempt him to break all palace protocol and use it.
Thom Pierce is sixteen years older. Old enough to know he should ignore his prince’s less-than-subtle flirtation. He’s been burned by a higher-ranked boy before. His job and reputation are at stake if the palace catches a scandal unfolding under their noses.
Wren needs the part of Thom that he’s kept locked away for years. If the young prince wants to be taken as seriously as his older brothers, he has to grow up fast. Thom’s rules could help Wren become the man Thom knows he can be in time for the Royal Ball… or they could attract the very attention that forces them apart forever.