Written for comment_fic on livejournal (a multi-fandom prompt fic community)
Prompt was for S/K, engine room
"But we always do it in the engine room!"
"Because it's fun in there!"
"Come on, Kaylee, let's try it in a bed."
Kaylee rolled her eyes.
"I'll let you tie me to a bed."
"Then you'll also let me tie you to the pressure gauge."
"A pressure gauge isn't sexy."
"Says you, Mr. FancyPants."
"Come on, Kaylee, I have bruises everywhere."
"I was willing to be twixt you and the floor, but you insisted on me being on top."
"It would be ungentlemanly to let you be hurt."
"Well, I think it's unladylike to bang you in a bed. How about that?"
"Is it the fear of being caught? Because we could do it in someone else's bed. Jayne's?"
"Too small. And guns under the pillows."
"How do you know that Kaylee?"
"Never mind. The Cap'n's bed?"
"It's really lumpy."
"How do you know that Simon?"
"Never mind."
"You know what, Simon, forget it. Beds aren't sexy. See this?" She opened the engine panel so they could see the inner workings of the most powerful part of the ship, full of rough but precise movements, thousands of perfectly controlled explosions giving off heat and spark and deep groaning sound. "THIS is sexy."
Simon looked at Kaylee, her face reflecting the orange flickering coming from behind the open panel, the heat already giving her a thin shimmer of sweat.
"You know, Kaylee, you're right. Your engine room is quite sexy."