You chose a tickle story

Road trip

Prompt: could you do one where a 16 year old sister and her 19 to 20 year old brothers go on a road trip with one of her cousins driving and the brothers get bored while on the way and tickle their sister.
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"Ow"
"Ow"
"Ow"
"Ow"
"For god sake, Brandon, stop poking your sister!"
"Ow"
"Ow"
"Ow"
"OW, Sean, tell him to stop!" Liv cried.
"Brandon, I told you, stop poking your sister!"
"It wasn't even me that time!"
"Ugh, fine. David, stop poking your sister, you'd uploaded to be the mature one!"
Liv snorted at that comment which earned a slap from David.
They were currently in the back of their cousins car, going to visit their grandma. But putting three siblings in the back probably wasn't the smartest move.
"Ugh, Sean, can I please sit up front with you" Liv begged.
"As much as I'd love that" he replied sarcastically. "Half of the luggage is here and we can't fit it anywhere else."
"We could have left it behind!"
"We could have left you behind" Brandon said which he regretted after his sister hit him.
After five minutes of peaceful silence, to Sean's pleasure, he was peacefully concentrating on the road, until-
"Eeep" Liv squealed, batting David's hand away, only to be poked in her side by Brandon.
"Stahahapp" she weakly laughed, smacking both their hands away. But four hands against one was never in her favour.
"But we're bored" David said, lightly wiggling his fingers in her sides. Now unfortunately for Liv, their grandma lived in California, so she decided to wear a crop top. I know you thinking, why would someone with two older brothers and occasionally her older cousin, who usually tickle her to death every chance they get wear a crop top? Well, Liv was planning ahead and in her defence, she didn't think she was going to get attacked in the car.
"Cahahammmeee ooohohonnn guuuyysss" she giggled m, trying to hold in her laughter. But all of a sudden, they both started attacking her bare sides.
"NAHAHAHAHAHOOOOOOO" she squealed by surprise and moved about in her seat trying to get away. But her seatbelt and the fact she was in the middle were preventing her from doing so.
"SSEEEEAAANNNNNN, MAHAHAKKEEEE THEEHEMMMM STAHAHAAHAPPPP" she laughed, hoping her cousin would have mercy on her. But him being 23, only 2-3 years older than her brothers, she should have known he'd side with them.
"Nah Liv, to be honest, I'd being doing the same, if I wasn't driving" he laughed, looking into the mirror and seeing his little cousin in fits of laughter.
"AHAHAHAHHAHAAHAHAHAHAHHAHAHAHHAHAHAHAGAHHAHAHAHAHAHHAHAHHAHAHAHAHHAHAHAHAHAHAH" Livs infectious, desperate laughter filled the car, while she did all she could to push her brothers hands of her sides, but all her pushes were barely noticed.
All of a sudden, her denim shorts were now her arch enemy. David moves his fingers down onto her inner thighs and started kneading them which he noted made her laughter go significantly higher.
"Hey Brandon, try this" he laughed, demonstrating his actions which made Liv make a squealing noise.
"EEEAHAHAHAHAHHAHAHHAHAHAHAHHAHAHAHAHHAHAHA" squealed Liv, fighting the sensations. Brandon copied David's actions, and two of them doing this made the feelings for Liv unbearable.
"CAHAHAMMMEEEE OONNNN GUAHAHAYYYYSSSS STAHAHAHAPPPPP" she laughed, having given up on fighting them.
"What did she say Brandon?" Brandon pretended to think intently, his tickling fingers still assaulting her thighs.
"I think she told us to tickle her armpits" he said casually assaulting a very surprised Livs underarms.
Liv was in hysterics. She could barely breath and was unable to even string a simple sentence she was laughing so hard.
But when she really lost it was when Brandon started scribbling and teasing his fingers all over her stomach.
Had her seatbelt not been on, she would have ejected through the car roof. But instead she bounced as much as she could desperately while she tried to push both their fingers off.
"AHAHAHAHAHAAHAAHAHAHHAHAHAHAHAHAHHAHAHAHHAHA NAHAHAHHAHAHAHAHHAHAHAHAHHAOOOOOOOOOOO STAHAHAHAHAHAHPPPPPPPP IIIIIIIIII CAHAHHAAHNNNNTTTTTT TAHAHAHAHAHAHAHAHKKKEEEE IHIHITTTTTTT" she squealed shaking around in the seat.
"Awwww, come on, your laugh is so cute. Why would we ever stop?" Brandon teased, squeezing all of her stomach which bought out different yelps from Liv.
"Yeah, you do this toddler giggle whenever we do this" David said, sticking his index finger into her belly button. Which indeed it did. A childish laughter came out. It was how Liv used to laugh as a child and as much as the boys would hate to admit it, they missed it.
When Liv was on the verge of passing out, fortunately for her, Sean put a stop to it.
"Alright guys, stop before she dies" he jokingly said. Liv panted in the middle seat trying to compose her left from all the torture she had just endured.
"I hope I can stay at Grandmas forever" she said, crossing her arms and refusing to make eye contact.
"I am offended" Brandon laughed.
"Yes, maybe she should be punished" David smirked.
"Noooooooo, I'm sorry" she said, momentarily and quickly hugging them both.
They both laughed at their sister before rolling their eyes. This was going to be a long journey.