Best Man by Lily Morton

Zeb Evans doesn’t do messy.
The product of a disorganised and chaotic childhood, Zeb likes order and control, and as the boss of his own employment agency he can give that to himself. Life runs along strict lines and he never mixes business with pleasure. Everything in his life lives in neat, alphabetized boxes. Until Jesse.
Jesse Reed is Zeb’s complete opposite. He’s chaos personified. A whirling cyclone of disorder. He’s also charming and funny and a very unwanted distraction.
Which is why it comes as a complete surprise to Zeb to find himself asking Jesse to pose as his boyfriend for a few days in the country at a wedding.
Zeb doesn’t do impulsive, but as the time away progresses, he finds himself increasingly drawn to the merry and irreverent Jesse. But can he bring himself to break the hard-won lessons he’s learnt in life? And even if he can, how could Jesse be attracted to him anyway? He’s so much older than Jesse, not to mention being his boss.