Resist Me Not by Amanda Meuwissen

Be a good parent.
Be a good partner.
And you can pretend I don’t exist.

Trey Fisher is like any refined gentleman. Well-dressed, well-groomed, with a steady job that brings him all around the country for travel writing about interesting hot spots, and he even calls his mother weekly.
He also murders the abusive filth of the world if they happen to cross his path.
During one such venture, spotting a fight in progress, Trey comes to the rescue of a handsome young doctor about to be assaulted by his ex, and his carefully constructed life spirals into beautiful turmoil. No one has ever captured and kept Trey’s attention quite like Walker, and experiencing these new feelings becomes an addiction he refuses to let get away.
Walker Hammond is like any doctor about to start his fellowship. Deep into studying, practically without a social life, and wishing he had never gotten involved with his latest ex, Curtis.
He also never thought he’d fall for the serial killer who murders Curtis in cold blood.

During the last several weeks of his vacation between completing his residency and starting his fellowship, Walker meets and quickly falls for charismatic Trey, after Trey saves him from ending up worse than the scar Curtis leaves on his cheek. But when Walker discovers Trey’s true profession, fear paralyzes him, and he has to decide if the pleasant ways Trey makes him feel are enough to keep dancing with the devil.