Gibbs grinned. “Except when you do, unofficially.”

Now Charlie was really suspicious. “When I do unofficially, it’s because Simon drags me in—something you’ve never done or tried to do. So why now?”

“Spur-of-the-moment impulse? Maybe I miss my old skipper.”

“Gibbs, what’s going on? Why are you being nice to me? If Liv’s dumped you and you’re looking for a new bit on the side with similar DNA, forget it. I’m a married woman—not the Liv kind. The boring sort that only screws her husband.” God, that sounded priggish. Charlie felt almost ashamed as she remembered the promiscuous risk-taker she used to be. She distrusted moral-majority attitudes on principle, and was only faithful to Simon because she was in love with him and the thought of being with another man turned her stomach. In the abstract, she had no problem with sexual infidelity as long as the individuals involved weren’t her exasperating younger sister and her surly former DC.

She’d often wished she loved Simon less, so that she could enjoy a secret sex life he knew nothing about. Involving someone Olivia worked closely with, ideally—give her a taste of her own medicine, see how she liked her sister trespassing on her territory.

Gibbs and Liv had been having an affair for several years. It had started on the night of Charlie and Simon’s wedding and, despite Charlie’s hopes that it would end disastrously and early, it had proved irritatingly durable. So far it had survived Gibbs’s becoming the father of twin girls and Liv’s marriage to another man—a wedding Gibbs had attended. He and Liv had gazed at each other longingly over the heads and between the torsos of the other guests, seeing nobody in the room apart from one another, while Dominic Lund, Liv’s husband, had done his best to talk to all the people Liv was busy ignoring. No doubt he’d imagined, incorrectly, that he was the romantic hero of his own wedding. It was one of the strangest social occasions Charlie had ever attended.

“Bit on the side?” Gibbs frowned. “Is that what you think Liv is to me?”

“Do you prefer ‘mistress’?”

“How would you feel if I mocked your relationship with Simon?”

“You mean how did I feel, on the many occasions that it happened?” As soon as she’d said it, she regretted it. Charlie hated thinking about that part of her past: getting engaged to Simon with everyone knowing they hadn’t yet slept together, all the mockery they’d had to endure, the speculation at the station about the cause of Simon’s abstinence, heavily weighted in favor of its being somehow Charlie’s fault . . .

“I haven’t mocked you and Simon, separately or together, for a long time,” Gibbs said.