For the speedwriting thing: Willow and Tara? Or what about this from your prompts tag "Platonic Xander and Willow tickle fights. Like they fool around and clumsily try to overpower one another and know all eachother's worst spots because they're childhood friends. And then they try to get Buffy in on it, but quickly learn that they'll never get the drop on her (unless she lets it happen.)"
(omg I almost forgot about that prompt it is beautiful, I love me some tillow but I gotta do the scoobies one)
…
“No- no!” Xander cried, kicking his feet as Willow grabbed his ankle in a death grip.
“Prepare to face my wrath!” Willow exclaimed with a faux-evil laugh. She scribbled her nails up and down his sole, making him shriek. “You squeal like a little girl when someone gets under your toes, it’s adorable, dork.”
“Oh yeahahaha? Well you-” Xander used all of his strength to flip around onto his back, leaning forward and wrapping his arms around Willow’s waist from behind, tickling her whole midsection. “You start begging about 4 seconds into someone tickling your sides!”
“Nahahaha! Dohohohon’t!” She leaned back, trying to push his hands away.
“What on earth are you two doing?” Buffy’s voice cut through their laughter.
“Hehehehelp! He’s killing mehehehe!” Willow squealed, unable to fight back since he was behind her.
Buffy rolled her eyes but found herself smiling, “I think I could probably help you out there.”
“Hey! Hey that’s cheating!” Xander gulped. Buffy pulled Willow free with ease.
Once she was free, Xander and Willow shared a looked. In unison they jumped at Buffy, dragging her into the fray…only to realize they were no match for someone who literally kills demons and monsters on the daily. She easily maneuvered away from the two, “Really?” She laughed.
“Right. Slayer.” Willow shook her head. “Well, it was worth a shot.”
“Doesn’t this all seem kinda silly in the first place? I mean, we’re in high school.” Buffy asked.
Willow shrugged, “I don’t know, it’s kind of fun to just let loose and goof around. Xander and I have been getting into shenanigans like this since we were kids.”
“Right! It’s like an ode to our childhood, still young at heart.” Xander added.
Buffy thought about it for a moment. “Alright.”
“Alright what?” Xander asked.
“No slayer strength. Free for all fun.” Buffy smirked, “What, afraid you’re still going down?”
Willow and Xander grinned, jumping at her. All three of them were giggling and rolling around on the floor. They were right, Buffy couldn’t remember the last time she felt this care free and had had this much fun.