1. You're both always down to eat the same thing, making dinner planning super easy.
2. Personal space is not a thing with you two.
3. You're honest when it comes to your outfits.
4. And just about everything else.
5. You're there for each other in the most dire of situations.
"Ron, listen to me very carefully. I lost my father when I was ten. I don't have any brothers. And Ken Burns never wrote me back. So I am not getting married without you there to walk me down the aisle. End of discussion."