cycle sister

When you’re so close to your girls that your periods sync up. You become cycle sisters.

Bae we both need a tampon because we’re cycle sisters. Love you bae.

by S Cal January 18, 2019

Surprise Sisters

When two friends randomly text each other or shout “Surprise” at any moment.

“Hey Morgan, guess what?”
“What is it?”
“SURPRISE!”
“Yassss Surprise Sisters!”

by All The Tea Sis January 27, 2019

sister scandalous

A friend that is being more scandalous than usual

Paige’s nudes were sister scandalous

by Itsreallymeboi September 22, 2018

sister data

Sharing your info (if you are a girl)with your sister.

Hi sis i need a private talk with you i wam going to give you some sister data .

by Earth Worm Sally May 15, 2018

Sassy Sister

That one friend that is sassy and annoying but is also the best!

Bsf 1 - She's soooo sassy
Bsf 2 - yeah cause she's a SASSY SISTER?!?!

by duuuuuuuuudeee November 7, 2019

sister-in-law

1. The wife of one's brother.
2. The sister of one's spouse.

My sister-in-law is a good person.

by Elivaldeq November 24, 2019

Head sister

When you and your best friend get scooped by 2 dudes at 3 AM and yall don’t have anywhere to go so you guys pair up in the car (front seats and back seats) and give suck dick together

“Omg that makes us head sisters!”

by boh bhiiii May 22, 2019