Taylor Swift and everyone.
Cara Delevingne and Kendall Jenner, a.k.a. CaKe.
Marc Jacobs and Kate Moss.
According to the most fashionable friends on social media, you’re not REALLY close until you have matching tattoos, or an acronym at the very least. There’s Cara Delevingne and Kendall Jenner, also known as CaKe; then Cat McNeil and Jordan Barrett, who have “CatDog” tattooed forever on their forearms; plus Lena Dunham and Jenni Konner have their own newsletter together, Lenny. Then, there are the BFFs who have proved they mean it over time, like icons Kate Moss and Marc Jacobs, as well as Naomi Campbell and Sean Combs who refer to each other as brother and sister.