Here's a fluffy ficlet about Spike and Dawn, as discussed by Spike and Buffy...
Bedtime Story
“A bet?”
“That’s what I said.”
“You stopped wearing nail polish… because of a bet?”
“Yep.”
Buffy is giggling. “So, what, you said ‘If I can’t kill twenty demons in under a minute I’ll give you fifty bucks-’ ”
“Quid.”
“Fifty quid, right, and the other guy says ‘Hah, fifty quid? Better yet - you have to stop wearing nail polish! Mwahaha!’ …something like that?”
“It wasn’t like that.”
“So what was it, then?”
Spike rolls over to look at her, raising an eyebrow. “If I tell you, you’ll drop it? No bringing it up at Slayer meetings to embarrass me?”
She tries to look serious and confidencey, but her eyes stay mischievous. “Well… okay. Probably.”
“It was when you were dead. Back in Sunnydale.”
“As opposed to all those other towns I’ve been dead in?”
Spike bites her bottom lip gently for a moment. “Hush.”
More mischievous looks on the verge of giggles. She stays quiet.
“I’d been babysitting Dawn, taking care of her, you know. Teaching her to… cook.”
“Okay. I take it that by ‘cook’ you mean ‘play poker’?”
He just raises an eyebrow briefly, before continuing.
“So one day, she gets an idea for this fun new game called Let’s Steal The Vampire’s Cigarettes And Watch Him Pine For Them. Would have gone out for more, but I’m in charge - have to stay there to make sure no big nasties come and eat her.”
“Sure.”
“Eventually she says I can buy them back off her - twenty quid apiece.”
“Yikes. That’s extortion. Go Dawn.”
“Oi, whose side are you on?”
“My sister and her masterful plans for getting money?” A glare is directed her way, and she amends, “Or… the extremely sexy vampire with a nicotine addiction who’s going to do something really nice for his girlfriend who always supports him? Bad Dawn. Bad.”
Spike moves one hand swiftly under the sheets, and Buffy shrieks and rolls away, grinning.
“Nope.”
“You don’t…”
“Not yet. Finish the story.”
He sighs, and continues. “Well, even if I’d wanted to pay her, I couldn’t. She’d already won most of my money while we were… cooking.”
“What, ‘Give me three dollars and I’ll add more salt’?”
He ignores that, with a slight smile. “That’s the whole strategy. Get me craving a fag, get me distracted, win every round. Bloody brilliant, really.”
“So… what’d you do?”
“What any self-respecting big bad would do: bet her she couldn’t down an entire bottle of whiskey. And once she was good and sozzled, I ate her.”
“Spike!” Buffy smacks his shoulder, looking appalled. “That’s my baby sister! Whiskey?!”
“Okay - I lied. I didn’t eat her.” He tucks a strand of hair behind her ear, and adds, “And it was milk.”
“You… bet her she couldn’t drink milk?”
“One whole carton, mind. And there are three people living in the house, so they’re getting the gallon…”
“You didn’t.”
“Yeah, I kinda did.”
“She puked?”
“Oh, sodding everywhere. Not really a diet I’d recommend trying.”
“That’s just evil.”
He looks at her challengingly. “Your point?”
Buffy just glares.
“She managed the full thing, though. Every drop. And I’m standing there with no money, vomit all over the kitchen floor, and still no bloody cigarettes. And I lost the bet.”
“Yeah - about that. What happened?”
“Well, the deal was, if she couldn’t drink it all, I get the smokes back, no charge. If she can…”
Buffy waits expectantly.
“Then I have to let her give me a makeover.”
Silence.
Followed by more silence.
Followed by shrieks of laughter.
“A-”
“Yeah, yeah, full thing. Clothes, hair, makeup, the works.”
“And you-” More laughter from Buffy, smothered by the pillow she’s hugging.
“She brings me this t-shirt that says ‘Sensitive Sweetheart’ in pink letters, and she dyes my hair to match. Only in spray-on colour, thank god. And then she does my nails.”
“She-” Buffy dissolves into giggles, again, but then calms herself down and tries to look serious. “And… the black?”
“Hey, you try sitting there letting a schoolgirl paint your nails in pretty colours while singing the Rainbow Bright theme song, and see if you can still take the goth look seriously.”
“Good point.”
Spike shrugs. “Haven’t worn any since.”
“Well, I’m glad.”
“Yeah?”
“Mmm. I like your hands without the polish.” She threads her fingers through his. “Plus, knowing Dawn, there are probably photos. Imagine the blackmail possibilities…”