It’s when you fucking destroy your sister cause she’s a little prick.
“Ima fucking upper cut the shit outta you Stephanie”

“Why?”
Cause it’s National uppercut your sister day
by MexiAlan October 30, 2019
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You've always waited for this moment but you never had the occasion, now you do
Oh where are you sisteeeer, its timeeee, today is beat up your sister day
by Martichucho August 7, 2022
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December 5 is the day you should say your fake sister and if y’all like it then y’all should date fake sister or fake brother go for it ! I mean try summ new!!
by Lowkeykeen December 5, 2020
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National punch your sister day is every February 20th, where you can punch your sister all day long
Today is national punch your sister day
by Alyankees12 February 20, 2023
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December 5th national date your fake sister or fake brother for a day no regrets you have to date them no cheating
“It’s December 5 yo why be single” or “it’s national date your fake sister day let’s go”
by Lowkeykeen December 5, 2020
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