sib-friend 

when a friend becomes fully integrated into your family

when sib-friends talk to each other: how's mom doing?
...imma live in your basement

sib-friend by mox+gam November 29, 2020

Subfriend 

Someone who is more than an acquaintance, but less than a friend. Usually someone you share a mutual friend with, but are never invited to hang out with them and your mutual friend.

Hey, did you hang out with everyone from high school during break?
Nah, they all triflin' subfriends smh.

acquaintance friend subfriend fake friend petty high schoolers petty college freshman high schoolers college freshman

Subfriend by Igotucuz February 28, 2016

Subfriend 

A friend, who is also a Submissive human being and is more than willing to do anything to please. Can be equated to a friend with benefits, a subfriend is usually only a subfriend to one person.

Not to be confused as a lesser friend. A subfriend will be a friend when needed, and take abuse when required, and give anything they can to make a friend happy.

David is an old friend, but when times are tough I prefer to talk to dray who is my subfriend, he would literally do anything for me..

Subfriend by Anon233353 September 30, 2021

Sisfriend 

Somebody who is both your sister and girlfriend at the same time. Pretty simple.

"Oh yeah! She is my sisfriend!"

Sisfriend by StyleSister15 June 26, 2024