You can go to their house and literally do nothing, without it being boring.
In fact, you can go there and nap, and they won't bat an eyelid.
You don't need to always have ~interesting~ conversations, and you can have good chats about the most mundane things.
You can look worse for wear around them and you know they won't care.
You can ugly-cry around them.
Even if it's over something really small.
You help yourself to food whenever you go to their place because you know where everything is.
And you can take off your bra once you get through the door and be free.
You accompany them for big hair changes when they go to the salon, for emotional support.
It never feels embarrassing to bring up a bodily function.
You can ask them weird sex-related questions without fear of judgment.
You don't mind asking them to check whether you smell alright.
You perform hair checks on each other to see if it can go one more day without washing.
You happily run errands with them, and you know they'd do the same for you.
You can take shitloads of pictures when you're out together for Snapchat/Instagram and they won't judge you.
And you'll sift through each other's selfies to find good ones to upload.
You update each other on the growth of your body hair.
If you're broke, you don't have to subtly hint you'd rather "stay in", you can outright tell them.
And you can voice your ~existential questions~ to them because they won't think you're weird.
You send each other Snapchats with the weirdest facial expressions you can muster.
And if you don't talk or see each other for a little while, you never worry because you always pick up right where you left off.