Undercover Lovers is the complete erotic LGBT crime trilogy by Ellie Barker:
Secrets and Spies
When Nikolas Jinsen, police mole, meets an unusual woman named Sky, he thinks he's just in for a night of pleasure. But he's soon pulled into a world of mafia dealings, stolen documents, hacked computers and kidnappings - not to mention a woman with a taste for exhibition, a Queen who demands payment in pleasure, and Sky herself; unusual, intoxicating, and wanting more than Nikolas may be willing to give.
In Bed with the Enemy
Nikolas Jinsen, police mole and mafia odd-job man, is given an ultimatum; stop seeing his girlfriend, or lose his job. When a hasty attempt to keep both goes wrong, he does the only thing he can think of: he lies. But with his new roommate a member of the elite gang that Nikolas has been tasked to look into, and his assignations with his girlfriend constantly interrupted by calls on his services as a lover, Nikolas finds that work isn't all fun and games.
For Queen and Country
Nikolas Jinsen, police mole and mafia odd-job man, is usually pretty easy-going - both at work and in the bedroom. But there's one thing he doesn't forgive, and when an opportunity for revenge comes up against the woman who insulted his girlfriend, Nikolas is in… even if the woman in question is the powerful mafia boss who is currently retaining Nikolas' services as a lover. Revenge is best served hot - and steamy.