Disclaimer: I don't own serenity or firefly, or the crew, cast, or even the costume designs (though I want those) However, the OC's in this story are mine, and I will fight you for them.
Spoilers I guess if you haven't seen the movie.
So here goes nothing
A noise coming from the kitchen roused Mal from his thoughts. As far as he knew, Jayne was in the kitchen. And Jayne and noises were bad combinations, usually precursors to an explosion, or the product of a long drunken nights.
He climbed out of his quarters and proceeded down the metallic corridor. They had just left the port a day ago, and he had no idea what could get Jayne this antsy this early.
Reaching the kitchen he drew his weapon at what he saw. There was Jayne, sure enough, gun pointed at a woman, who was returning the favor. She was dressed roughly, a white tank, grimy with years of wear not from being dirty, cargo pants, and a regulation brown jacket.
"What are you doing on my gorram ship?" he asked roughly They hadn't picked up any passengers at port.
"I was asking her the same question cap't," Jayne continued to point his gun.
"And that's mighty fine. Now, you have two guns pointed at you. Now I would think that now would be a fine time to be talking to me, miss, " he shrugged, gun still pointed at her.
"I'm a stowaway," she smiled, and before either could blink she had two guns in her hand, one pointed at Mal, the other at Jayne, "and I'm the best marksman in the galaxy."
"That's a pretty big boast, miss."
"That's no boast cap't. I could drop both of you before you touched the trigger," suddenly, her guns were being held by her thumbs, and she was putting them on the floor, "However, I doubt the rest of your crew would appreciate that, and what good is a ship without a crew."
"Don't think that we're not partial to guests, miss, we have a bad history with stowaways. The last one was my wife."
"That bad?" she smirked, "And no, I have no interest in you."
"It's both a relief and a mighty sorrow to here you say that. Jayne, "the bigger man nodded in assent, "get her to a secure room." As Jayne led her out of the room, Mal studied her guns, lying on the floor. They were older, but well crafted. They were also well worn from years of use.
"Hey cap't," Kaylee entered the room, "Serenity's all nice and shiny, so we should hold together till at least the next port. What's wrong cap't?" she said, looking at the two guns.
"Haul out the champagne and prepare a feast, Kaylee, we have a guest," Mal picked up the guns and started back to his quarters.
"Alright cap't."
"Kaylee, I'm joking."
"About the champagne, or the guest?"
"The champagne."
"Hey, cap't."
"What Kaylee?"
"cap't, I'm pregnant," He walked back, guns in hand.
"You're what? How?"
"C'mon, cap't, do you have to have me explain the birds and the bees to you?"
"No, that's not what I meant. Now, Kaylee, what are you doing getting pregnant?"
"Cap't, it's not like I planned to get all pregnant."
"And now I've got to protect you and an unborn. Oh, isn't that great. On top of that, the fathers, the fathers…"
"Simon."
"Exactly. He's on the run. He's a fugitive from the Alliance."
"But he's Simon too. And now he's the father of my child," Kaylee smiled, "'sides cap't, we're not exactly on the right side of the law."
"Depends on what you term right," she frowned at him, "Fine. But c'mon Kaylee. You're like a daughter to me. A daughter I've exchanged dirty jokes with and seen naked. Okay, maybe not exactly a father-daughter relationship. Maybe more of an open relationship. Yeah, open."
"It's okay, cap't, I understand," Kaylee went back to her quarters or at least in that general direction.
Meanwhile Mal had bigger problems. Like an expert marksman who had stowed away on his ship, and how he had to get a permanent replacement for his pilot. Granted, River was good, when she was sane, but she was unpredictable. Not for the first time did he wish Wash hadn't died.