1pm, Christmas Day

"Hey you two. Are you gonna come sledging with us?"

"Sure Charlie, just give us five minutes to get ready. We didn't think you were going so soon."

"It has been an hour since we decided on it Day, or didn't you notice?"

"Ha ha Charlie, you're so funny. C'mon Mulder, let's go get changed so we're not too cold out there."

"Oh no ...You're not going up together are you. We'll never get going!"

"Charlie...I'm warning you. Cut it out."

"Why do you guys need to get changed anyway...can't you keep each other warm?"

"That's it Charlie...I'm gonna get you for that."

Scully dived at her brother who quickly spun out of her way, still chuckling. She chased him round the room until he collapsed into one of the chairs trying to catch his breath from all the laughing. She pounced on him without giving him a chance to recover and began tickling him relentlessly, obviously a tactic she had learnt from their childhood. Charlie twisted round in his seat so he could reach her and started to tickle her in return. The two of them continued to laugh and squirm and tickle one another until Maggie came into the room with Peter and the twins.

"Dana! Charlie! Stop it this instant!"

The two abruptly stopped at the sound of their mother's shout and both sprung guiltily from the chair, avoiding Maggie's eyes. Dana tried to sort out her hair and Charlie started to fix his shirt as if they could pretend they weren't doing anything wrong, forgetting they were adults. They eventually looked up at Maggie and caught the twinkle in her eyes. They both released a short chuff of laughter and then looked at each other, a gleam now in both of their eyes. They put on serious faces and pointed at each other.

"He started it."

"She started it."

Maggie kept her face serious as her two adult children behaved exactly as they had done when they were children. She lost it though when Scully and Charlie both pouted and started chortling at their antics.

"Oh my gosh. That's exactly the face they used to pull when they knew they were in trouble, Fox. The two of you haven't changed a bit really. Have you? You just pretend to be grown-ups, you're just big kids though aren't you?

The two of them nodded happily whilst grinning at each other. Scully caught Mulder's slightly astonished smile out of the corner of her eye and, as she turned to face him, she saw that the three kids were all staring at their dad and Auntie Day as if they had both gone nuts. Turning back to Charlie, she saw that he too had noticed his children's stares and was trying very hard not to laugh. Scully crouched down and motioned for the twins to come to her. When they did, she pulled them both close and stage-whispered to them.

"That's how you beat your big brother when he starts teasing you when you're older."

"Excuse me...Beat your big brother, Day? When did you ever win?"

"I always won Charlie."

"Nuh uh. I don't think so Day. You always ended up on the floor squealing for mercy."

"I did not."

"Did too."

"Did not."

"Children behave. We have guests present!"

"Mom, who won, me or Day?"

"I won Charlie, I always had to break you two up or you would have never stopped. Anyway...shouldn't two of us in here be getting ready for sledging. The snow will have melted by the time the two of you finish arguing over who won so why don't you call a truce. Then Dana and Fox can go get ready to join us."

"Not a word Charlie...not a word!"

After that warning, Dana turned to go up the stairs to get warmer clothes on. She stopped half way up to wait for Mulder and, after making sure Charlie was watching and the kids were still in the other room, she jumped into his arms. She attacked him with a vicious kiss and, realising what she was doing, Mulder stopped walking and started to lower them both onto the stairs without releasing her mouth. Charlie laughed, then threw his hands up in mock despair and walked back into the lounge shaking his head. They broke the kiss when they realised he had gone and Scully began giggling. Mulder laughed too and then brought their mouths together for a gentler kiss, both still lying on the stairs. They were interrupted by a loud cough and looked up to see Tara gesturing frantically for them to get up. Instantly recognising what she was trying to tell them, they hastily stood and had started to walk properly up the stairs before Bill came out of his room with Matthew.