A/N: While getting in gear for the final season, I was re-watching Season 4 and 5 of Lost and became extremely interested in the dynamics of Kate and Aaron's familial relationship. Particularly the first year or so that they're off the island together. So I've written up what I hope is a believable story involving that plot line. I'm also warning that it may get a little AU but only relationship wise. Anyway Happy Holidays and please enjoy.
Disclaimer: I own nothing. Except an idea.

We Should Say He's Mine

Chapter 1

Motherhood

"I think we should say he's mine."

"What?"

"We could say that I was six months pregnant when I was arrested and that I gave birth to him on the island. No one would ever know."

Light streams through the circular window, stretching across the floor and up the side of the bed. The waves outside slosh against the boat as it dips lazily into the Indian Ocean. They're heading for Indonesia, Jack hasn't told the rest of them yet, but it's one of the first things on the agenda.

Beside her on the bed, a small whine comes from a laundry basket that she and Penny fashioned into a makeshift crib. The bed, even being a rudimentary cot on the private boat is too soft. But like Jack said, "At least someone was able to sleep."

Aaron lets out a yawn that sounds more like a coo, but the action turns sour as his eyes scrunch together and his hands ball into tiny fists. Before she can even comprehend her action, she lifts the infant away from the coddling blankets and to her chest for comfort before he cries.

The gesture mollifies the baby, who lies against her shoulder with one hand stuck under his head and another pressing into her collarbone. The noise in his throat turns to a content gurgle instead of a strangling cry and she pats his back because she doesn't know what to do.

It's the honest truth that the closest she ever came to being a mother before last night was a negative pregnancy test. But suddenly she has both feet in the water and another life relies on her without nine months of waiting or years of planning ahead. She has no idea what to do with a nine week old baby, or how differently to act to pass him off as only five weeks.

Aaron's fingers curl against her chest as she feels his face contort. He emits a dull whine because her shoulder muffles his mouth. The hand that supports him brushes against the soft fabric of a fine dinner serviette that Penny gave to her to use as a diaper. The boat doesn't have a backlog of diapers, but if everyone agrees to Jack's plan, she really can't show up one hundred and eight days marooned with an island born infant in name brand diapers.

When she finds the material in place with no wetness or change, she places her cheek next to Aaron's so he can feel her smile, "You must be hungry." She only assumes. She should be hungry as well but with the rocking of the ship and the events of the last few days her stomach hasn't been able to manage more than apple juice and some saltine crackers.

His skin begins to cool under her fingertips as her empty hand reaches for one of the cotton blankets, "Let's get you something to eat." What could he eat? Sometimes on the island they fed him Dharma brand milk or a little bit of coconut milk. On the boat milk is fine, but again sailing back to civilization with a carton of milk after three and a half months doesn't make sense.

When can he eat solid food? What type should she give him? Her hands make quick work of bundling the blue blanket around the essentially naked child. A thought dashes through her mind to ask Jack, but immediately she vetoes it. By Jack's attitude last night, she knows he's against her raising Aaron. She doesn't know why. Maybe the added stress or responsibilities she'll have to undertake. Maybe he thinks she's doing it out of guilt. Maybe because it will need the fabrication of a second lie. Maybe because it subtracts from her virginal qualities, but the tape footage of her and Sawyer in a polar bear cage probably took care of that.

What if Claire's family wants him? Claire was going to L.A. to give him up for adoption, right? Couldn't she just live in L.A. and a truce be called? The rest of the group causes a bigger problem. Sayid, Sun and Hurley may not approve of a wanted criminal passing off their forgotten friend's son as her own. But who else will raise him? She can't abandon him.

He stops shifting under her hands as one of his hands breaks free from the blanket. He stuffs it into his mouth, sucking on his fingers and looking up at her with big blue eyes that hold innocence. She smiles and tickles his cheek with a finger, watching as his eyes light up and his toothless mouth grins. No, she can't abandon him.

Aaron calms again as she lifts him with the blankets and gives thanks to the fact that Sun left early in the morning. Though they used to be close friends, Sun hasn't exchanged more than a few words or expressions to her since the freighter. She seems needlessly cold to Jack and barely communicates with anyone. She knows it's because of Jin and her broken promise.

As her toes touch the linoleum floor in the guest room there is a light knock at the thin wood door, "Kate?" His voice is gravelly with the last three sleepless nights and she pictures him resting his forehead against the coolness of the door in the morning air with a hand waiting on the knob to turn it on her word.

She smiles, "Come in," and as he opens the door she realizes that she hasn't made any attempt to fix herself up since her shower yesterday. Her hair is rabid with the use of shampoo and because she air dried it. She also slept in the same clothes that she wore all yesterday because Aaron and Sun were asleep.

Jack smiles a morning greeting as soon as he sees her and though it may not be noticeable to anyone other than her, his smile falters a little in the corners of his mouth and his eyes when he sees Aaron. "I came to see if you were up yet." He meets her where she's standing and his hands come out to examine the fading gash on the side of her face like he did after a certain boar hunt so long ago. "Maybe you can actually keep down something substantial today."

"I've been eating," she counters as her eyes dart away from his, a piece of hair escapes from her ratty bun and Aaron gurgles.

"Barely," he lets his hand drop but the warm smile still persists, "Try eating more grains. They help absorb stomach acid so you won't be so nauseous."

She sighs and gives him a playful eye roll because he reads her so easily. It frightens her to have such commonality with someone after being alone for so long. She tries not to think about it, "I've never been good on boats."

"Because you can't run?"

He doesn't mean for the question to be so harsh, but it hurts her. She blinks twice and when he's oblivious to her discomfort she answers, "The waves distort the horizon. It makes me sick."

"Well hopefully we'll be off this boat before sundown," his grin is different now hopeful and just a little bit arrogant. "After breakfast I've asked everyone if we could meet upstairs for an important discussion. We need to get them to lie."

"I know."

Jack pauses for a split second and finally notices her shift in mood, "Penny's cooking up another great breakfast," he changes the subject and points to the door, "Lots of pancakes that could help settle your stomach."

Before she replies, he places a hand on Aaron's back. It's so large that it covers to the baby's shins, "He's probably hungry too."

She doesn't know if he says it to inveigle her into coming upstairs, or as a reminder that she needs to look out for Aaron's well-being. Or even as an abstract way to show that he does care about the baby and they could deal with Aaron together. So she nods her head and smiles and lets him lead her out of the room with the same large hand on the small of her back.

Thanks to all who read and reviewed. Please as questions if you have them. Second chapter coming soon.