Two people shit into the same toilet bowl
When the toilet was blocked, Kirsty and Alan had no choice but to become Shit Sisters
The combination of the mind altering drugs : Xanax , Aivan , and Klonopin.
I did the three sisters mix and don't remember having 4 babies.
To perform cunnilingus on another member of your sorority, typically as a friendly favor rather than a typical hookup or relationship
Sister 1: It's been too long since I've gotten laid, I wish someone would sister suck me.
Sister 2: I got this.
a group of similar aged women who meet regularly to discuss life's experiences
my urban sisters are coming to brunch on Sunday
When you and your friend fucked the same dude. Not necessarily at the same time.
You fucked Jon last night?!? *HIGH FIVE* I fucked him back in high school! We're now PETER SISTERS!!!
Two girls that share a relation to each other such as sisters that do anything in their power to flirt with anything that has a penis. Mostly refered to as skank.
Bob: Man did you see those girls flirting with me?
Sam: Yeah they were acting like such Lehnen sisters.
Teenage girls use it to express distaste for someone.
Sometimes they use it to address their friends.
"Ayyyyy what's up sister snaaaaakes!!!"
"OMG what a sister snake am I right."
"Don't talk to me sister snake."