It's not easy to maintain a friendship with Taylor Swift.

Just ask Lorde, who knows first-hand what it's like to call on of Hollywood's most followed (and scrutinized) celebs a best friend. The New Zealand-based pop star provided an interesting metaphor for their years-long friendship during an interview with The Guardian, comparing it that of someone who suffers from an autoimmune disease.

"It's like having a friend with very specific allergies," Lorde admitted, referencing Swift's A-list status. "There are certain places you can't go together. Certain things you can't do. There are these different sets of considerations within the friendship. It's like having a friend with an autoimmune disease."

But unlike some of her non-famous confidantes, having the 1989 artist in her circle comes with major perks. Lorde explained, "It's an element of wanting to stick together. Because it can be so scary to do this. These friendships, they're about having a hand put on your shoulder by someone who knows. They're about hearing, ‘I've done it, too."