He doesn't really consider his eavesdropping a bad habit, although he's aware that there are some people--and Nick, understandably, is almost certainly one of them--who would probably disagree. After his surgery, he does it almost without meaning to. The whole world seems suddenly so loud again, sounds sharp and bright, conversations that are none of his business pressing into his ears without any real effort on his part. That's how he first finds out. He's just walking down the hall, and it's not his fault that the door is open and neither of them notice him.

"...working another double," Nick is saying from inside the DNA lab. "I'm sorry, Greggo. I can't get out of it."

Greg sighs. "Figures. No, it's okay. Go do your superhero thing; you know where to find me when you get done."

"Yeah. I really am--"

"It's okay. Seriously." Greg puts his hand out, touches the inside of Nick's elbow, and Gil blinks. The contact is brief, but significant.

Nick ducks his head and smiles, then steps back. "I'll see you around," he says, and heads out into the hall. Gil steps back, cocks his head, and watches Nick walk away.

Interesting.

He doesn't say anything. It makes him happy, in a wistful sort of way, to see them and besides, he's curious to see how long they can keep it under wraps.

They do better than he expects. Greg doesn't seem like the sort to just sit on something like that and Nick--he's beginning to get the idea that Nick's much better at keeping secrets than he would have expected. It makes him wonder what else Nick keeps locked up inside his head, but he doesn't ask.

Catherine tells him he needs to get a hobby, and she's probably right. Curiosity is an old habit, though, and it gets him through the slow shifts. He used to watch Sara, but that's dangerous now. He's a moth to her flame, and that's a battle with temptation that's hard enough on its own.

They seem happy. It doesn't affect their work, but he's still careful not to put them in the field alone together when he can avoid it. No need to tempt fate.

A year passes, and then another. Catherine knows. He catches her watching with a motherly, indulgent smile when they show up a few minutes late one shift, freshly showered and wearing identical guilty expressions.

Gil lectures them both, separately, and pretends to believe both of their stories about setting the alarm clock wrong.

And then there's Sara, and his life is finally full enough that he stops paying so much attention to Nick and Greg. They're still together, he thinks, although his only real clue is the occasional careless touch, the way they stand too close when they don't think anyone is watching. It's only now that he's trying to keep an office romance under wraps that he fully understands just how much work it is.

It's a few weeks after the beating that he finds out they're living together, and that's only because he decides to stop over and see how Greg's doing in person.

An old Norwegian woman answers the door, and after a conversation consisting mostly vague muttering on her part and not-so-vague hand-waving on Gil's part, she directs him to the manager's apartment, which is conveniently just across the hall.

"Greg?" the manager says in a surprised tone when Gil asks. "Sweet boy. He moved out--oh, six months ago. Sublets the place to old Svana. I guess he rents a house across town with a friend now."

"Of course," Gil says. "Thank you."

When he looks up Greg's file later that night, he isn't that surprised to find that the contact information hasn't been updated. Not that it really matters. He knows where Nick lives, after all, so it's not like it'll be a problem to get in touch with Greg.

"Man," Nick says, stretching his hands out in front of him and rotating his wrists until the joints pop, "I am wiped. I think I'm getting old."

Catherine smacks the back of his head on her way out of the room, and he laughs. Gil shakes his head, smiling, and opens his own locker.

"Did you see that, Grissom? That was assault, right there."

"If you feel the need to provoke Catherine, you're on your own, Nicky."

"I get no sympathy around here," Nick says mournfully. He finishes lacing up his boots and stands up, pulling a windbreaker on. "See you tomorrow, Gris."

Gil nods absently, then remembers something. "Nick?" he says, and Nick turns. "When you get home, tell Greg to locate his cell phone and call me. I've been trying to reach him for the past hour."

"I--" And then Nick pauses, face going blank as Gil's words process. He tilts his head back to stare at the ceiling, blowing out a long breath, then laughs suddenly. "Shoulda figured. How long have you known?"

Gil smiles a little and shrugs. "I didn't," he admits. "Not for sure, anyway, until just now."

"But--"

"But I suspected, yes. Greg sublet his apartment a year ago and moved in with you. It could have been just to split the bills, but if that were the case, you wouldn't have gone to such great lengths to keep it a secret."

Nick runs a hand through his hair, looking sheepish. "And we thought we were doing such a good job."

"You were. I wasn't sure until you just told me."

"And you're...okay with it." The baffled expression on Nick's face makes him want to laugh.

"You're not his supervisor. There's no conflict of interest. And it's not any of my business." All of which is true enough, but that's not why he hasn't said anything, and Nick is smart enough to know that.

"Well, no," he says slowly, "but that's never really stopped you before, has it?"

"No," Gil agrees. "It hasn't."

He doesn't offer anything else. Maybe he should explain about Sara, and how hypocritical it would be to get on Nick's case, but he doesn't.

Nick gives him another perplexed look, but he doesn't seem disposed to press the matter. With his hands stuffed in his pockets and his cheeks flushed, he looks like an oversized kid, and Gil decides to take pity on him.

"Go home, Nick," he says, as kindly as he can. "Get some rest."

"Right," Nick says. For a moment it looks like he's going to say something else, but then he just shakes his head. Gil watches him shoulder his backpack and head out of the room, smiling.

It might have gone on like that indefinitely, but then Sara is kidnapped. And afterward things don't really go back to normal. It's not just the two of them, either--the whole team is thrown off, and Sara glides around the labs like a short-tempered ghost.

They're at the diner. Gil has allowed himself to be dragged out of his office for steak and eggs and bad coffee more for Sara's sake than for any other reason, and he's not paying any particular attention to Nick or Greg.

So he hardly even notices when Nick brushes his knuckles against the back of Greg's hand, then pulls back as though he's just remembered where he is. He's done the same thing himself, often enough, with Sara; it can be easy to forget sometimes and he's watched the two of them dance around each other long enough that it seems normal. Catherine and Warrick don't say anything, either, but Sara suddenly slams both hands down on the table hard enough to rattle the china.

All five of them start and stare at her, but she's glaring at Nick.

"That's it," she announces. "I'm sick of this."

Nick blinks at her. "Uh, Sara--"

"Shut up." She points at him. "If I have to watch this anymore I'm going to scream. We all know about you two. We've known for years. So just--stop pretending, okay?"

For several seconds, the table is dead silent, and then Greg clears his throat, lips pressed together in an unsuccessful attempt to suppress a smile. He slants a sly glance at Nick. "I told you."

"I--but--" Nick blinks at Sara, then looks around the table. Catherine gives him an indulgent smile. Warrick leans back in his chair, arms folded, chuckling. Gil shrugs and spoons up a mouthful of runny eggs, and Nick finally ducks his head, gobsmacked expression giving way to laughter. "Oh, hell. I'm an idiot."

"I wasn't going to mention it," Greg mutters, but his smile is blinding when Nick reaches across, very deliberately, and takes his hand.