Sunastara & the Venusian by Jess K Hardy

On this deep space pleasure cruise, love is in the recycled air

As the hospitality specialist aboard an infamously debauched interstellar pleasure cruise, Sunastara Nex never mixes work with pleasure. But she knows more than most how little the universe cares for rules and order. For example: the most worlds-shattering one-night stand of her life just became the newest member of her crew.
Freddie is as gorgeous as she remembered, still unbearably tempting, and still very interested. Unfortunately, he’s also strictly off limits. Until he comes up with the wildest seduction strategy this side of the wormhole.
But while Sunny and Freddie hide their romance in a world of make-believe, a very real threat puts their ship and possibly the entire Known Universe at risk. Faced with the unknown, they’ll have to decide whether they’ll fight for a future together, or let the gravity of their pasts tear them apart.