Author: CruorLuna (Alison)
Rating: K+
Category: NCIS: Naval Criminal Investigative Service
Genre: Romance, angst
Pairings: Jibbs, Gibbs/Diane
Characters: Jenny and Jethro
Summary: It was instinct. Nothing more, nothing less. Just instinct … and them.

Disclaimer: I don't own anything you recognise from the show.

A/N: Based off of a line in the second oneshot of my Killers series: The first time they had kissed had been in London, and then they hadn't spoken for three months. My own interpretation of how Gibbs and Jen went from partners to lovers, with an angsty twist. I do enjoy the scenario where their relationship evolves through sexual tension, and that's definitely in here, but considering how difficult they both are, I always thought there had to be something more complicated in it – after all, that's why we love them, really. So this is just a theory I have on how the changes in their relationship could have been made more difficult (like everything else Jibbs-related). I'd love to hear your thoughts.

It was instinct that told him that there was something different about her from the moment they met. Sure, part of it was the way she held her own against his attitude, and the way she wasn't afraid of him, but it was mostly instinct. A gut feeling. He was known for his accurate instincts, and he was sure they weren't going to fail him this time. He was right.

It was instinct that told her that he needed someone to challenge him once in a while. That same instinct led her to taunt him mercilessly, by any means necessary. She stood up to him when he tried to shoot down her ideas; confronted him when she thought he was wrong; teased him when he was moody. She didn't think anyone had ever dared to tease him on the job before, but instinct told her that that was the kind of partner he needed. And he was always teaching her to follow her instincts, after all.

It was instinct that told him that he was in way over his head when Morrow sent them undercover in Europe together. He was in the middle of an extremely messy divorce, and the last thing he needed was to spend long periods of time in confined spaces with his partner – his attractive partner. Her teasing of him had escalated beyond belief over the past weeks, and not just about his job, either. Their banter had become heavily sexual; flirtatious and challenging. He didn't like to back away from a challenge, but there was something about Jenny Shepard that he couldn't pinpoint, that kept him at a distance. He supposed it was his instincts screaming at him to get out before he did something he couldn't take back. For the first time in a long time, he found himself ignoring his instincts.

It was instinct that told her that she had gotten under his skin. It was also instinct that told her that he liked it. It was instinct that made her question whether the teasing she had enjoyed had always just been about irritating him, or whether there was something deeper there. It was a distinctly different instinct that told her that her body craved his touch; that there was most definitely some unacknowledged attraction there. It was instinct that told her to get up her courage and do something about it. It was instinct that told her that the timing was right; that made her pull him to her in that car and kiss him right there, in the middle of a stakeout.

It was instinct that made him respond.

It was also instinct that made him pull away, knowing that they couldn't do this – not here, anyway. They laughed about it, joking that it was about time, but his instincts were still warning him that this was wrong. Or at least that something was wrong. His instincts were once again proven right by a phone call as they drove back to the hotel, their shift being over. And it was instinct that told him that he had to leave after hearing what the caller had to say. His instinct also told him that she wouldn't like that very much.

It was instinct that told her that he wasn't being totally honest with her. There was more to his sudden departure than just a form that needed to be signed for his divorce. It was instinct that told her that the awkward phone call, on which she had tried not to eavesdrop in the car, had not come from Diane's lawyer, but from the woman herself. It was something slightly more than instinct that told her that he was uncomfortable with the situation; that he was nervous about having this conversation. It was instinct that told her that this was probably for the best anyway; that she couldn't afford to get involved with her partner – with her boss – undercover anyway. It was that instinct that made her push him away, telling him that she didn't care one way or the other anyway.

It was instinct that made him doubt that statement. It was instinct, too, that told him that although she'd never say it in so many words, Diane needed him at her mother's funeral. It was instinct that told him not to question it when she leaned on him for support at the graveside. It was instinct that had him wrapping an arm around her shoulder and holding her as she cried. It was instinct that told him that no matter what else had happened between them, this situation was special; he couldn't say no when she turned to him for comfort. It was instinct that pulled him towards her like a moth to a flame, intent on driving away the pain, even if just for the night. It was instinct that had him staying with her, holding her close to his naked body long after they were both spent and she had finally fallen asleep. It was instinct that prevented him leaving in the night; waiting to say goodbye. It was instinct that had him refusing her offer of breakfast, knowing that the night before had been the hardest part; that she didn't need his brand of comfort any more. It was instinct that told him that this goodbye was their last.

It was instinct that told her that something had happened when he was back in DC. The softened way in which he said Diane's name, compared to the bitterness of a week ago, only served to confirm her suspicions. It was instinct that had her pushing him even further away; snapping at him every time he opened his mouth; refusing to even let him attempt to explain. It was instinct that told her that he was trying to take their relationship to the next level, despite whatever had happened in Washington. It was instinct that almost – almost – had her surrendering to the lust in his eyes. It was also instinct that stopped her.

It was instinct that had him spilling the truth by only the second night back in her company, in Marseilles. It was instinct that told him that she needed to know the truth or there was never going to be anything more than hostility between them. It was instinct that told him that she was softening towards him, even as he confessed that he had slept with his now ex-wife. It was instinct that had him swearing to her that it was never going to happen again.

It was instinct that made her believe him.

It was instinct that had him drawing her into his arms, pinning her body under his on the bed and claiming her for his own.

It was instinct that had her letting him.

It was instinct that had him pulling her to him, spooning her from behind and holding her as they fell asleep together. It was instinct that told him that she needed the closeness; the reassurance.

It was instinct that had her reaching for him again before either of them was fully awake.

He had taught her to follow her instincts, just as he always followed his own. Both of their instincts were telling them that this was a mistake; that no matter how unbelievably right it felt, that it was still wrong on so many levels.

But Lord, if those instincts had ever mattered less.

A/N: Okay, so I thought I'd mess around with a slightly different writing style to go with this mildly obscure plotline. I'm not sure about it, so let me know if it worked, okay?

Thanks,

Alison xx