When I read m/m, I like the men hard. I like my science fiction hard, too. If it's offered as romance, I like the relationships developed. So I was not very happy with this story, because one out of three isn't enough.
From the opening scene, where Rider has been captured and bound under the assumption that he's an infected spy, come to suck what's left of unchanged humanity into the "hive," the sexual come-ons are fast and thick. "The infected are always ready to f***," because exchange of bodily fluids passes the nano-virus around. An insane AI has created the nanos as a way of subjugating humanity for its own unexplained purposes. Rider is marked as infected but has thrown off the infection, or so he'd have Sutton, his interrogator, believe, although he has the residual need to nail everything standing. Sutton feels the draw but he's supposed to be immune to the wiles of the infected.
This is one of the few human enclaves left, but the lights are still on, the water's still running, and the med-techs have enough of a lab inside the Tower of London to be able to run tests. There must be a limit to what they can do, because the humans test-f*** (author's term) such spies. The humans have fought very hard to survive but perform this sort of suicide mission regularly, which made no sense to me at all. Once Rider convinces everyone he's really not infected, just a pheromone-shedding, bragging sex machine, they release him into the general population, and draft him for a suicide defense when the compound is about to be overrun by the infected.
Time spent waiting to die is always best spent having sex, so Rider and Sutton do. This provides the answer to the main problem, although now Sutton is now so drawn to Rider that his previous immunity is gone completely, as is his refractory period. In terms of the plot, this is both a good thing and nearly required.
There was very little consistency in the science fiction aspect; while I don't need to know why exactly the AI embarked on this experiment, I do think its methods needed to be internally consistent. The nano-viruses behaved like viruses at times, but then behaved like programmable devices at other times, and flipped back and forth as convenient, giving the infected some strange abilities and quirks. Frankly, it all seemed like several s/f buzzwords had been cobbled together to provide an excuse for Rider to talk about everyone he'd had sex with, including one of Sutton's long term lovers, who was used as a test-f***. Rider has no compunction about needling Sutton about Annabel or the others, nor about discussing a long line of willing infected partners. Rider actually has very few lines that are not directly discussing sex he's had or would like to have.
Once the breakthrough regarding the infected has been achieved, it's straight to "I love you," for Sutton, which is the more astounding jump. Nothing Rider has done is remotely loveable, and he's served to expose all the cracks in Sutton's existing relationship, which is a little on the kinky side but nothing too outrageous in a stressed environment like the human enclave. Sutton is, BTW, still actively engaged in this relationship when Rider enters the enclave. Sutton's response to having this pointed out is to declare love for the pointer, who can provide mind-blowing sex. Hmm.
Unfortunately, in terms of romance, there is no relationship development; in terms of science fiction there is no consistency, though the fast pace tends to obscure this. Read strictly as erotica, it's okay but heavier on the sex talk than the sex acts. I honestly have no idea what group of readers would find this a wholly satisfactory story.