So, this just came to me in a burst of inspiration when thinking about how Cal and Gillian might be around Christmas time… I know it's a bit early, but it's the Christmas episode next week, and I don't want any of my ideas cropping up on the show and it looking like I just stole them LOL.

Disclaimer: I own nothing. Nata. Zilch.

Christmas Cheer

"Merry Christmas Dr Foster!"

"Merry Christmas Heidi!" Gillian returned the greeting. She was strolling down the corridor of the Lightman Group, quietly humming 'Deck the Halls' to herself and smiling at everyone she met. It was the day before Christmas Eve, and the festive spirit seemed to be everywhere. The large Christmas tree in the entrance was decorated with large gold and red baubles and twinkling fairy lights. Streamers, tinsel and more lights were strung around doors and desks, and everywhere she went, people were laughing, singing, and having a good time. Loker had made some Christmas punch, which he was dishing out in the kitchen; "non-alcoholic," he'd assured Foster. "The alcoholic version is in the fridge; I'm bringing that out at 5".

Gillian couldn't help but feel happy at this time of year – the lights, the decorations, the party spirit. She reached Cal's office, and pushed open the door, stopping briefly to survey the scene before her. Cal's office looked no different than it did on any other day. No decorations, no lights, nothing. He was sat behind his desk, looking at something on his computer.

"Good morning," she greeted him, walking further into the room and setting her coffee down on his desk.

"Are you ready for the meeting with Robert Davis?" was his reply, and Gillian resisted the urge to roll her eyes.

"Yes, Cal. We'll be fine. Your office is looking beautiful, by the way," she added sarcastically.

"I suppose you think I should put foliage and energy-wasting lights everywhere, do you?" he asked, dragging his eyes away from the computer to look at his partner.

"Oh come on Cal, stop being such a Scrooge." She giggled at the look on his face.

"Hey, I like Christmas, me. Especially since Em was born. Presents under the tree, nice Christmas dinner, cheesy jokes in crackers… Christmas is good."

"But?"

"But I don't see the need to bring it into the workplace, or to celebrate it ages before the day itself. I mean, we're here to work. And today might be the last day before we take a Christmas break, but everyone's acting like it's…"

"Like it's what, Cal? A reason to celebrate?" she teased him.

"I just don't go in for all this over the top, cheery, tacky stuff. I mean, have you seen the Lab? Bloody Santas everyone, and a snowman that plays a tune whenever you get within five feet of the thing. It's a pain in the arse."

"You're hopeless." She laughed.

"You're loving this all though, no doubt," he commented, and she answered him with a bright smile. "Thought so. It's very you, Christmas."

"Over the top and tacky? Thanks." She stuck her tongue out at him and reached forward for her coffee.

"Happy," he corrected her.

She took a long sip of her coffee, then put it back down on the desk. "You know what – you are going to join in the Christmas festivities today. I've just decided."

"Oh have you now? And since when are you the boss of me? I was married for ten years, I've had enough of people making decisions like that for me."

"I'll be generous," she said, ignoring his last comment. "I'll give you a choice of ways in which you can get involved."

Cal sat back in his chair, his hands folded in his lap as he surveyed the woman sat in front of him. Her earrings, he suddenly noticed, were in the shape of snowflakes. He tried to hide a smile as he waited for her to give him his choices. He wasn't lying when he said he didn't really like Christmas at the office, although he'd never begrudged his team the opportunity to celebrate however they chose. His office, on the other hand, would remain untouched by the over the top Christmas fever that swept the whole world from, it seemed, about two months before the day itself. Despite that, he was intrigued to know what Foster was going to say. She was sat in front of him, wearing a smile that reminded him of Emily on discovering that Santa had been. Over the top and tacky Christmas could be, but surely something that made Gillian Foster smile like that couldn't be all bad, he mused.

"One," she said, ticking the options off on her fingers. "You come carolling with me around the building."

"Absolutely not."

"I'll let you choose the songs?"

"Absolutely not," he repeated.

"We'll drink eggnog as we go?"

"Abso-bloody-lutely not," he said. "I hate carols and I hate eggnog. Whose half-brained idea was it to put egg in a drink, anyway? People only drink it because they think it's traditional, I bet you half the people who drink it don't even like the stuff."

"Eggnog rant over?" she asked, and he exhaled loudly.

"Yes."

"Good. Okay, option two. You let me decorate your office with some nice fairly lights, maybe a dancing snowflake or two…"

"No way."

"Tastefully done, I promise."

"There's no way I'm letting you loose in here with your box of decorations," he said, pointing his finger at her.

"Fine." She let out a dramatic sigh. "Well, you've rebuffed options one and two. That only leaves option three."

"Which is?" he asked warily.

Gillian didn't say anything, just reached into her bag and pulled out a sprig of mistletoe, and watched Cal's eyes widen slightly. "Option three is to partake in a traditional Christmas custom," she told him, dangling the mistletoe in front of her, a mischievous look in her eyes.

Cal pretended to consider things. "Is it too late to change my mind about the carolling?"

"Yes," she answered, her voice slightly huskier than it had been a moment before.

"Well, I suppose there are worse Christmas customs," he said, pushing himself out of his chair and walking around the desk until he was right in front of Foster.

She stood up, the mistletoe in her right hand, and held it above both their heads, looking at him expectantly. He paused for only a second, before leaning towards her and capturing her lips with his own. The kiss was soft at first, and he gave her the chance to pull away if a brief, chaste kiss was all she wanted. It wasn't. Wrapping her free arm around his neck, she pulled him closer, opening her mouth to him and pressing her tongue firmly inside his.

Surprised, but no less pleased, Cal returned her kiss, raking his fingers through her hair. She smelt like cinnamon and orange – decidedly Christmassy, he thought.

Breaking apart at last, Gillian scanned his face with her eyes, relaxing a little when she saw him smile. "Now, that wasn't too bad was it?" she asked in a whisper.

Cal grinned at her. "Better than carolling, at any rate."

She pretended to hit him, and he laughed. "Congratulations, Foster. You've officially imbued me with the Christmas spirit."

"Good." She strode towards the door, and moments later had fixed the mistletoe above the door frame. "Now, I hope you'll be abiding by the laws of mistletoe all day, Dr Lightman. It's a serious Christmas tradition."

Cal nodded. "I will, don't worry." He walked towards the door and glanced up. "Oops… looks like we're here again." He leant forwards and brushed her lips again, and felt her smile.

"Careful, Cal. You'll earn a reputation as someone who actually likes Christmas."

"Well, I certainly like this part of Christmas."

Laughing, she opened the door and stepped out, bumping into Loker as she did so.

"Oh, sorry Eli," she said. "Merry Christmas."

"You too," he said, stepping into the room.

Gillian caught Cal's eye, and her gaze flicked upwards for a second to the piece of mistletoe now hanging directly above Cal and Loker. Cal instinctively took a step back, giving Gillian a "don't even think about it" look, and she laughed. "Now, Cal," she said, her eyes glinting wickedly as Loker looked on in confusion. "Rules are rules."