“Spray tans on light skin last an average of five days. Yours looks to be at the midpoint. Something you got done over the weekend, then, and you didn’t remove your wedding band for the process. Only now it’s gone and there’s an embarrassing ring of white skin in its absence.”

Bosman glanced at his hand before quickly shoving it into his pocket.

“You’ve got a touch of lipstick on your shirt collar too,” Larkin continued. “Sure, you might have come to the scene after some afternoon delight with your wife, but unless you’re still in the honeymoon phase of your relationship, this is doubtful. Plus, you’d have no reason to remove your ring around her. Ergo, an affair. And not with a beat cop—she wouldn’t bother with lipstick. Another detective perhaps, but I think you enjoy the power trip of the ‘d-e-t’ title too much to share the glory. So a young and impressionable administrator at the Ninth.”

Doyle had said nothing during the back-and-forth, but he did sigh once or twice.

A furious blush had worked its way through Bosman’s tan, and he’d finally suggested that Ricky be brought to his precinct, but that he’d allow Larkin and Doyle first dibs on an interview.

“You’re mad,” Larkin stated, staring at Doyle. They stood in a hallway outside one of the interview rooms at Precinct 9, with Doyle leaning against the wall, scrolling on his phone.

“I’m not mad,” he corrected in that ever-smoky voice. “I’m trying to read.” He must have sensed Larkin’s stare, because Doyle raised his gaze after a beat. “I wouldn’t have used an affair as leverage.”

“I couldn’t possibly care any less who Bosman is actually sleeping with.” Larkin slid his hands into his pockets and began to pace the hall. Upon his return to Doyle, he added, “It was the only clear deduction I had of his person at the time.”

“Hm-hm.”

Larkin passed a second time. “If you don’t like the way I work—”

“We’re partners now. That’s no longer a valid fallback,” Doyle cut in.

“I don’t know what you want me to say, then,” Larkin murmured on his third pass.

“I would like you to apologize to Bosman.”

“No.”

“And,” Doyle continued calmly, as if Larkin hadn’t just so brazenly disagreed, “I’d like, with regard to personal relationships, that you keep those intuitive deductions to yourself. I know you can’t help it, and if you want to blurt it out when we’re alone, that’s fine. But don’t weaponize someone’s romance. In fact—” He paused and looked up from his phone again. “—that’s out-in-the-field, rule three: love and sex can only be used for good.”