He should know by now that assumptions can be dangerous.

It's Abby's fault. Probably, he should be thanking her right about now, but he's kind of busy.

Abby decided to decorate for Christmas. She usually does her lab, but this year it has crept out and about and around the building. She's even put a holly wreath on the director's door, and pleasant a man as Tom Morrow is, Gibbs isn't quite sure how she's gotten away with that.

Holly, though, is not the problem right now.

Abby being Abby, she'd put on her best, darkest, most shiny red lipstick this morning, and has taken every opportunity to get it on whoever gets caught under the mistletoe she's put up all around her lab.

Gibbs made an effort to wash the colour off his cheek, though he hasn't been completely successful. DiNozzo hasn't even tried, and Gibbs rather suspects his senior agent likes everyone knowing he's been kissed.

Ducky, ever a sport, has perfect kiss marks on both cheeks and a red splodge on his nose, and Palmer actually has a smudge of red around his currently very smug smile.

Tim came back from the lab looking flustered, red smeared on his mouth and lipstick staining the collar of his shirt in several places. It looks like he got a double or maybe triple dose, and Gibbs suspects their on again off again relationship may now be on again.

The problem, though, is Kate. She didn't come back from the lab with lipstick marks on her cheek - she came back with her lips expertly painted with the stuff. Deep, ruby red, lush and shiny. That is definitely a problem.

He's all but weaned himself off admiring her hair, noticing how nice it smells, and wondering if it feels as silky as it looks. He'll admit he can still be distracted by her pert backside if she bends over right in front of him, but that's just being human. Not that he usually cares to compare himself to them, but McGee and DiNozzo aren't immune either. He no longer runs his gaze up and down her legs at every opportunity, wishing her skirts were a little less modest. And when she pins him with those deep brown eyes, he is able to concentrate on responding to her sass and her challenges without feeling like he might drown in chocolate.

But her mouth... Ahh, her mouth. That is still a weak point. He is still blindsided when she smiles widely in his direction or seems pleased to see him. He still wants to hold her close and keep her safe when its corners turn down and she looks like she needs comforting. He can still completely lose track of time while she chews thoughtfully on the end of a pen. And when she licks her lips...

Putting her at a desk in his sight line? Probably not one of his best moves in terms of productivity, though arguably a damn fine idea nevertheless.

When a date comes up to collect her, or meets her in the parking garage at the end of the day, he still gets jealous that they get to kiss her. When he tries to sleep, it is her mouth that keeps him awake, and the imagined taste of her lips and her tongue that can force him to seek oblivion in bourbon and boatbuilding.

And now Abby has gone and painted it siren red.

It is definitely Abby's fault.

The mistletoe in the lab hasn't been too big of a problem. He's been aware of it since he went to deliver her morning Caf Pow, and has been careful to make sure for the rest of the day that whenever Kate is down there, he has urgent business somewhere else in the building. Anywhere else in the building. The head, if all else fails.

Abby is the only one who'd ever dare meddle in his private life, and he has no doubt she's aware he still carries a little bit of a torch for one Miss Caitlin Todd.

He'd been quite pleased with himself for avoiding the little minx's trap. He'd assumed he had outmanoeuvred her. Bad move. Pride had indeed cometh before his fall.

He hadn't intended to end up in the elevator with Kate. Spending time alone with her in a confined space is liable to remind him of all the things he's carefully trained himself to ignore, and while he occasionally does it anyway (he is a Marine after all - they're not supposed to hide from danger, even at his age), he tries to avoid doing so when she is looking particularly delicious. Like today.

Still, it shouldn't have been an issue. He is, after all, a Marine, and a pretty bottled up one, at that. Not to mention a Special Agent, a professional investigator, a noted and noticed interrogator. Stuffing his emotions, having a good (no, strike that, a great) poker face, an iron will, the ability to keep control of any situation? These are his stock in trade, the tools he uses daily to do his job. A gorgeous woman in crimson lipstick should not be an irresistible temptation. No matter how good she smells, no matter that he heard a hitch in her breath when he looked her up and down a little more thoroughly than he'd intended, no matter what. He isn't DiNozzo.

But apparently Abby has been thinking ahead. How she arranged this... Well, she is sneakier than he'd realised, for which he supposes he takes the blame. Evidently, she's picked up a few tricks over the years.

There's mistletoe hanging from the ceiling.

It wasn't there an hour ago, when he used it as his personal conference room as he so often does. Abby is still down in her lab running several batches of high priority DNA tests, and hasn't been up to the bullpen, never mind in this elevator, all afternoon.

He is still certain this is her doing.

However, he can't reasonably blame her for the fact he hits the emergency stop button about three seconds after the door closes.

And the look on Kate's face? Yeah, Abby probably isn't responsible for that, either.

He looks up at the mistletoe, and then back down at her. Pupils dilated? Check. Breathing uneven? Check. Cheeks flushed? Check. Mouth...

Oh, hell.

Mouth irresistible.

It was still supposed to just be a kiss. After all, it isn't exactly gallant to find a beautiful girl under the mistletoe and not kiss her. And while Gibbs may not be exactly gallant himself, he recognises an acceptable excuse when he sees one.

She isn't supposed to taste this good.

A brief kiss, lips barely open, just a memory of that sweet mouth to keep him warm at night... That could be ignored, forgotten, wouldn't change their relationship too much or cause any problems at work.

But when she moans softly, grabbing his lapels and pulling him closer, it becomes much more difficult to leave it at 'just a kiss'.

He gently cups her face in his hands, tilting his head to deepen it a little.

He's still trying to hold back, still half expects her to pull away, and it's almost his undoing when, instead, her tongue finds his.

He growls. The world blurs. This is not how it was supposed to go, says a surprised and concerned voice in the back of his head, but it's drowned out by the rest of him, which simply can't believe he has waited so long to do this, or how unbelievably good it is now that he's finally doing it.

She moans again, and her small hand caresses his jaw then slides into the back of his hair, holding him close, staking a claim. He's owned, vanquished, and he never knew it could feel this good.

Eventually the need for air and the small amount of self control remaining in his body combine to make him pull away, breathing hard. Her eyes take a moment to flicker open, and she is smiling that breathtaking smile.

"Merry Christmas," he mumbles, suddenly embarrassed, a little ashamed. Gibbs does not make out with his subordinates in elevators. Gibbs does not lose control. Gibbs does not break his own rules over a little bit of red lipstick.

She looks up into his face. She's still pressed close, too close to him. Somewhere in the last few minutes, without meaning to, he's wrapped one arm firmly round her waist, and his other hand is cradling the back of her head. She looks good in his arms, he thinks. He wishes he could keep her there.

"Merry Christmas, Gibbs," she replies, and her voice is... tender. She touches his face, smooths a thumb over his bottom lip.

"I... I..." He can't think what to say. He doesn't do apologies, but clearly he crossed a line here. If she was angry with him, he could deal with that. Angry women are familiar territory. She... Well, she's not angry. Even though she really should be. He's her boss, and...

She tugs at him, gently but firmly pulling him down till she can reach his mouth. This kiss is soft and gentle, a merging and mingling of breath and lips, a reassurance that whatever this was, she's happy about it.

When she steps away from him and flicks the emergency stop button, and the elevator starts to move again, he swallows a sigh. The moment is over, but he'll cherish the memory. Two kisses is two more than he ever thought they'd share.

He's ridiculously aware of her presence next to him, but he's still taken aback when, in the pause before the doors open, she takes his hand.

He lets her lead him out to the parking garage, where she spins around in front of him so suddenly that he almost runs into her.

She is looking mischievous, and the smile that hasn't left her face since the elevator turns wicked.

"You place or mine," she murmurs, the look in her eyes and the implication in her tone so surprising it takes him a second before he answers her grin with one of his own, and leans down for kiss number three, happy knowing this one won't, after all, be the last one.

Well, hell, he thinks. He really will have to thank Abby. Merry Christmas to me.