Hot Summer Job/Tell Bree that she could kiss Larissa for you
"If you really don't want Larissa to kiss me then you might have to take the kiss for me instead. She has a crazy look in her eye after all."
"No I don't..." Larissa defends herself, quickly looking away.
"Yeah!" chimes in Kylie. "He's totally right. It's like jumping in front of a bullet. But the bullet is Rissa's lips!"
Bree seems unsure of all this, but she isn't against it either. Certainly not after the stimulating experience that Kylie just provided to her. So she shuffles her way forward on her knees, slightly angling herself between you and Larissa in the process, perhaps subconsciously.
"Sit up," Bree weakly orders to Larissa.
Kylie helps out, dismounting her little sis and guiding her up from the mattress. Larissa doesn't need much help though. She bucks forward onto her hands and tucks her feet underneath her, full of positive energy after that make out session with her big sister. Sitting up straight she pulls her shirt down with a silly grin. Bree shuffles closer to Larissa until their knees are touching.
"I... I'm only kissing you so you don't kiss my brother."
"That's okay," nods Rissa. "I'll kiss you either way."
That comment makes Bree even more shy. She glances at you, tugs at her skirt, plays with her hair. Apparently being kissed by a girl is easier than kissing a girl.
"Just do it!" encourages Kylie from the sidelines.
With much hesitation, Bree drifts her way forward. Leaning in all the way to close the distance, she plants a soft peck on Rissa which lasts a few seconds. She breaks away afterward, sizing up everything. She must not have hated it though, because she leans in for another one. Neither girl is very exuberant about it, but they do at least try to move their lips and put forth a bit more effort than the previous peck, sharing a few very amateur if not outright clumsy kisses between them.
"Is that it?"
Bree pulls away sheepishly and wipes her mouth.
"Huh?" asks Larissa, still smiling.
"It's like neither of you knows the first thing about making out!"
"I thought it was okay," Bree whispers at the floor.
"No wonder I had to do all the work!" continues Kylie.
"You're older than us," counters Larissa. "Besides, when Sophie Timms was caught kissing boys under the slide our teacher told us 'nine year olds shouldn't be doing that'." Larissa wags her finger mockingly.
"Your teacher doesn't know anything," scoffs Kylie. "Let me show you. Stick your legs out."
Rissa is the first to comply, kicking out her legs into a V, running on either side of Bree. Your sis slowly follows suit, fumbling a bit as she is forced to throw her legs over top of her friend's. She starts to slide her way backward to make room when Kylie grabs her.
"Now get closer."
Kylie jerks on one of Bree's ankles, pulling her into Larissa. Your sis shoots a hand down between her legs, careful to keep her short skirt covering her crotch. But she inches forward, her thighs forced to part more and more as she gets closer to Larissa's body.
"You have to hug each other. Get really close."
Kylie grabs Bree's arms and helps to pull Bree the rest of the way in. Larissa grabs Bree's thighs and pulls up and inward, scooching forward as much as she wraps Bree's legs around her. Your sister meanwhile has to lean into Larissa just to keep her balance. In short order the two friends are front to front, their chests, stomachs and pelvises pressed together as they hug. Both girls have to crane their necks back a bit just to keep their noses from touching. Each of them are grinning demurely, staring into the other's eyes.
"Okay, NOW you can kiss."
Larissa engages this time, though with so little distance to cover you could easily consider it a tie. They're still slow and careful and pickup right where they left off, albeit with a bit more interest than before, arms wrapped around each other in a tight embrace.
"Tilt your head, both of you. Sorta like you're kissing sideways."
Both girls cock their head about 45 degrees. Their lips lock tighter now, each successive kiss displaying a bit more energy.
"But move your head around. Don't just stay in one spot. And switch sides sometimes too."
Kylie's instructions manage to get the two girls that much more engaged, each of them becoming a bit more animated and into it. Their ears and cheeks burn redder and redder with each passing moment, the heat between them rising, their lips smashing and smacking louder and faster.
"Move your hands too. You need to grab at her, pull her closer. Make her a part of you."
Your sister's hands had already started roaming by themselves across Larissa's back. Kylie's words only inspired her to move them that much more. And to also move her body. Bree starts involuntarily pushing herself against Rissa, which includes rubbing herself against Rissa's crotch. Larissa wants everything to do with this new activity and moves her hands down to grab Bree's butt helping to pull Bree tight against her pussy.
These preteen girls have been whipped up into a frenzy, kissing each other frantically as they grope and hump one another. They still look clumsy and jerky, but their blossoming sexual instincts help to compensate. Bree rubs up Larissa's bare back lifting her shirt up to her chest. Rissa's clawing and Bree's humping combine to flip up Bree's skirt and expose her ass, Rissa grabbing and squeezing the supple cheeks greedily.
You manage to look away long enough to spy Kylie sitting nearby while rubbing the front of her shorts. She clearly wanted this. Thanks to her, your ten year old sister has been making out with her younger friend for a couple of minutes now with no signs of stopping. The sexual energy in the room is getting intense.