Take a tin can traveling for weeks in space, filled exclusively with gay men - no women allowed, apart from the ship's AI, Mrs. Claus - and imagine the drama... and whatever you might be thinking now, is not correct.
While the ship might be run against every employment regulation I can think of, it is filled with believable characters who all have their own baggage and find support in each other.
The story is a page turner because of the arc, the characters, and the sensible descriptions of a well-thought through sci-fi world.
And yes, sex is there as well ... lots.