You Share Each Other’s Stuff
Best friends borrow stuff from each other, whether it’s clothes from one another’s closets or a car in case of an emergency. Even money isn’t out of the question, and that’s totally okay. There’s no hesitation because you both know that the other person will return everything on time and in one piece. You know they’re there for the long run, so who cares if they give you back your sweater 7 months later!