A/N: So, this is part of a series I actually started in 2009, writing a happy family Christmas for my favourite characters in various fandoms. It's set way, way in the future, probably in an alternate 'verse, and if you don't love Sheldon/Penny you probably won't approve of it, but hey, I kinda like how it turned out, even though I'm not much of a Shenny writer (I love it, but its not something I've done much). If you like it, pleae do let me know in the usual way ;)

Disclaimer: All recognisable characters belong to Chuck Lorre and other folks who aren't me. All other/new characters belong to Ultra.

X3. A Cooper Family Christmas

Neither of them had turned out to be geniuses like him. Sheldon wondered at the fact he even had the capacity to love children that were less intelligent than himself, and yet he adored them both from the moment they were born. Perhaps the true wonder was that he ever found a person that he was willing to create new life with, but Sheldon had long ago realised that if the phrase 'there's an exception to every rule' were to be taken literally, the exception to every rule in his life was always Penny.

Certainly he never imagined a day like this being a part of his life. Dr Sheldon Cooper never celebrated Christmas. He was present for his mother's celebrations as a child, obviously, but he never thought to be so hypocritical as to truly join in. These days things were different, Penny had made that difference. She wasn't overly religious herself but she believed in something, and more than anything she believed in her children having the best possible Christmas just because she loved them so much. On Sheldon's part, he had always been a scientist and dismissive of his mother's Christian teachings. Now he wondered more often than he didn't if there weren't some sort of greater power at work. He had no other way to describe how he and Penny had come to make a pair.

"Look, Daddy!" Kaylee yelled excitedly as she rushed towards his spot on the couch. "You'll help with all the experiments, won't you?" she checked as she showed him her chemistry set.

Sheldon bit his lip, a comment bubbling up about the sub par quality of the item, but he wouldn't let it out. If somebody had meant to do a nice thing for you or your offspring, you weren't supposed to insult it, Penny said, well, at least not until you got home away from the person you were going to bitch about.

"Of course, sweetheart," Sheldon told his daughter with a a smile that came that much more easily when he was talking to his children than at any other time it seemed. "Who bought you that gift?"

"Uncle Leonard," she grinned happily, before rushing off to compare her latest gift with her brother.

"Ooh, no," said Penny as she returned from the kitchen with hot tea for her husband and a coffee for herself. "That's a grumpy face. Sheldon, we don't have grumpy face on Christmas morning," she reminded him, sounding just a little too much like his mother somehow, but Sheldon let that slide this time.

"The gifts Leonard sent?" he grumbled. "Basic chemistry sets. Basic!" he repeated crossly. "For my children."

"Er, sweetie, first of all, they're our children. I don't remember you doing any pushing and screaming," she said matter of factly as she joined him on the couch. "And second of all, they're six years old and not quite the genius level you were at that age. Basic sets are fine for now," she assured him, patting his knee.

Sheldon turned to look at her to continue arguing, but found he just couldn't do it. Sometimes it still floored him how beautiful his wife was, and never more than in the moments when she wasn't particularly trying to be. Not long out of bed at some ridiculous hour of the morning, sleep rumpled, hair all over the place and dressed in an over-sized pink robe, she had never been more perfect. The smile that used to be solely for koalas crept onto Sheldon's face. Penny noticed and leaned into his side.

"That's better," she sighed happily. "The smile is always better."

She looked across the room to where her kids sat on the floor, practically swimming in Christmas wrap and cardboard boxes as they unwrapped gift after gift. They really had been spoilt this year, but she couldn't mind. The fact they could afford to spoil them made her happy and it wasn't as if they were always so lucky. Grandma Mary was sure in her element, as enthusiastic about every gift the children showed her as she could possibly be, even when she didn't understand what she was looking at. Luke was appropriately crazy about his toy lightsaber, and Kaylee couldn't stop bouncing over Klingon Boggle. Penny was still baffled by her daughter's affinity for a second language when she was still learning the basics of English, but it was fine. The kids had so much in common with their father, it made it all the easier to adore them than if they were just like her. Penny sighed. She couldn't imagine ever being happier than this.

"I never thought I could have this life," said Sheldon thoughtfully, catching her attention then. "I never thought for a moment that I wanted it. How is that possible?"

"That's life, sweetie," Penny smiled, kissing his cheek. "Always taking you by surprise."

An eruption of laughter from the others in the room had Penny getting up and going over to see what was so funny. It seemed Sheldon's sister, Missy, had unwrapped a gift from her eldest son and found it highly amusing. A giant tub of gummy worms. As far as the eight year old boy was concerned it was the greatest of all gifts, and the other kids sure seemed to agree. Missy just laughed, kissed little Joey's head and thanked him sincerely. After all, no matter the oddness of the gift, it was the thought that counted.

Even Sheldon understood that these days. So long he thought gifts had to be equal in monetary value or they were no good at all. It had taken a while for Penny to educate him to the contrary. He supposed he had really started to make sense of the sentiments she tried to convey as he found more and more people and things in his life that couldn't be quantified. There was no way to put a price on love, on a wife and children. These were gifts that had no real value, because they were beyond all the riches of the known universe. Sheldon was bowled over every time he realised these things, in those quiet moments when he sat alone watching his extended family in such a joyous, picture perfect scene.

Still, he was more comfortable on the side lines just watching it all unfold. Diving head long into such a moment, inane conversation with his sister and brother in law, childish chatter with his nephews, it was not Sheldon's idea of fun. Just to sit back and watch Penny, Kaylee, and Luke happily playing and laughing, in amongst family members that, despite appearances, Sheldon did hold dear. It was just about as perfect as anything ever could be.

They had eaten a good and hearty meal, played all of the games the kids had received amongst their presents, and the adults had drunk a great deal too. Christmas Day in the Cooper household sure had been one to remember this year, but the hour was growing late and the kids needed to be in bed as darkness fell around the glowing house of family warmth.

They all complained, but Missy and Penny were firm as they sent their babies up to brush their teeth, get into their PJs, and sleep.

"I had the best day, Mommy!" Kaylee was heard to say sleepily as she trekked up the steps with her brother and cousins.

Sheldon smiled as he heard her, then moved to begin clearing things off the coffee table. Mary got up too, following her son to the kitchen with dishes and glasses. He had been coming home for Christmas with Penny and the kids for years now, and yet this occasion had been different, he was different, so quiet and thoughtful. It made a mother worry.

"Shelly, now you're gonna tell me what in the world has been bothering you all day long," she said definitely just as soon as they were alone in the kitchen together. "Now, I know you better than anyone, and a mother knows when her son ain't himself."

Sheldon found her phrasing odd and was quick to tell her so.

"If I'm not me, then I wonder who you suspect me of being," he told her, immediately regretting the tone he knew his mother would not appreciate. "I'm sorry, Momma," he apologised, turning from the sink to face her again. "I'm not unhappy. In fact, I don't think I have ever felt quite as elated as I am today," he explained.

Mary looked at him oddly.

"And that's what's botherin' you," she realised, moving closer and putting her hands to his shoulders. "Honey, you ain't gotta worry about any of this goin' away. That wife of yours, she plum adores you, and those kids? Their Daddy means the world to them too."

Sheldon knew she was right, and he knew he was being illogical even wondering what his life would be without the family he had built here. Penny assured him so often that she was happy and still as completely in love with him as ever. There was no reason to suspect anything was ever going to break apart, and yet a fear existed in Sheldon's heart. Nobody could be this lucky, he was sure of it.

"It's a statistical anomaly," he shook his head. "For every action there is an equal and opposite reaction. For every up there's a down, for every good, a bad," he explained as best he could to a mother who knew little or nothing of science. "I can't help but come to the conclusion, that with so much currently in my favour, I must be headed for disaster at any moment."

Penny was in the doorway when he said that, hearing every word and feeling her heart constrict at the sound of them. She wanted to be pleased that Sheldon felt so blessed, but at the same time she hated he might be wondering when he would lose it all. Life hadn't always been kind to Sheldon Cooper, or to her either, but Penny needed him to know he had nothing to fear.

Mary saw her daughter in law hovering and smiled. She kissed Sheldon on the cheek, patted his arm and walked away. Penny moved in to take Mary's place in front of her husband and reached her arms up around his neck.

"Y'know, Kaylee was wrong," she said with a sigh. "I mean, yeah, this was a great day, no doubt, but she's too young to understand that you can never have a best day, because tomorrow could be even more amazing."

Sheldon smirked a little, knowing just exactly what she was doing. She heard his conversation with his mother and was trying to calm his fears. Sometimes he wondered if he was the only intellect in this marriage, or if perhaps Penny wasn't just another kind of genius.

"I once thought that Christmas 2015 was the best day of my life," he told her, his arms around her waist.

"Hmm, well, I think it's probably right up there in the top ten at least," she giggled, recalling their first kiss with the same giddy feeling that had come at the very moment she was thinking of. "I know you're not much for the real meaning of Christmas, Sheldon, but if nothing else, you have to believe in our family, in our love. I'd hate to think that was a faith you didn't have."

Sheldon shook his head slightly, almost imperceptibly and then leaned down to kiss her lips.

"Merry Christmas, Penny," he told her, tucking her hair back behind her ear.

"Merry Christmas, Sheldon," she replied, leaning into his touch. "Y'know, I have one more gift I've been waiting to give you," she whispered then, up on her toes and their noses practically touching as she continued. "You got any names planned for another son or daughter?" she checked with a grin.

Sheldon grinned at the realisation of what she was saying. There may not be such a thing as a perfect moment or a best day ever, but this one came close, no doubt about that.

The End

A/N2: To all those who read this story, Merry Christmas, Happy Holidays, Seasons Greetings to you and yours, as is appropriate :)