Goodness, almost everyone has at least two best friends: their best girl/guy friend, and their spouse/significant other. Then you get into people who are also on this level - someone's parents maybe, or siblings, maybe an aunt/uncle or cousin. That's at least THREE best friends right there, assuming one from each overarching category. Yeah, I don't think anyone on this planet has only ONE best friend unless they're a hermit who knows literally no one.
For everything else, there's mods...