Amy Andrews has many contemporary romances on her backlist, ranging from medical romances to small town to rugby sports romances and more. Undercover Billionaire is a few years old now (first self-published in 2020 and republished in 2025) and is set on a sun-drenched cruise ship, which is the perfect setting for this sexy beach read.

Aristotle Callisthenes isn’t keen on going undercover as a tourist on one of his family’s cruise liners but at his brother Theo’s urging, he’s doing just that. Trying to get to the bottom of the drop in passenger numbers and the higher turnover in staff on the Hellenic Spirit, he’s determined to find some answers. Widowed for a few years, a relationship is the last thing on his mind. But then he meets cheerful cocktail waitress Kelsey Armitage.

Kelsey needs her job with Callisthenes Cruise Lines. A bad turn with an ex-boyfriend who had stolen some money she’d received as an inheritance set back her plans to buy a beach cottage with her mother, but in a few months, and after several years of cruising, it will be time to get back on land permanently and settle down as she and her mother have been planning for years. On her latest week long Mediterranean cruise, the handsome stranger who visits her bar is someone she can’t forget, and when she discovers he’s forgotten his wallet, she finds his stateroom to return it. The attraction between them sizzles and a kiss is exchanged – one which Kelsey firmly states can’t happen again. She can’t be caught fraternizing with a passenger and risk losing her job. And as for Ari, he’s not exactly who he represents himself to be, and he already feels guilty about having to make up a story for his presence there. But in the close quarters of a cruise ship, meeting again is all too easy and the temptation is too great. A steamy forbidden romance with a clear end date ensues – but will it be so easy to say goodbye when the ship docks at its final destination?

I enjoyed reading about this cruise from the perspectives of Ari – as an owner with a vested interested in how the crew treats the passengers and each other – and Kelsey’s experiences as one of those staff members. Hearing from Kelsey’s side as a co-worker with other staff, having to deal with many different kinds of passengers, long hours on her feet and life ‘below decks’ adds a touch of reality to the otherwise fairy tale-esque billionaire romance trope.

Vacation flings always contain intense emotional scenes due to the shortened timelines, and in this story we have Ari struggling with the guilt of having feelings for a woman who isn’t his wife for the first time. Kelsey knows she is taking a big risk by engaging in a physical relationship with Ari – he could report her if things go sour and cut her plans short. But the sex is too good, and the way they make each other feel seems real even if digging deeper risks breaking the illusion.

The end of the week brings things into sharp focus and the hard work then begins of making a relationship out of a fling. Honesty first, compromise, and a willingness to take risks lead to their happy ending. Undercover Billionaire is a fun ride, and I’m looking forward to reading about Ari’s brother next in the upcoming sequel Below Deck Billionaire.