Their parents even text you sometimes to catch up.
You’ll automatically like any and all things they put on social media, even if you don’t actually like it. Solidarity sister!
You never have to ask to do anything in their house. This includes, but is not limited to: asking to spend the night, eating their food, using the bathroom, and stealing their clothes.
When it comes to clothes, you have no idea who actually bought what in each other’s closets.