Nothing lasts forever — especially celebrity friendships. Whether they've grown apart or have had messy, public feuds, one thing is for certain — these former friends are pals no longer.
Although Taylor Swift and Katy Perry might hate each other now, let's take a trip down memory lane and relive their better days.
MUST SEE: These 90's TV BFFs All Grown Up Will Make You Feel All the Feelings
Click through the gallery to see throwback pics of celebrity best friends before they called it quits.
"For years, I was never sure if we were friends or not," Taylor said allegedly about Katy. "She would come up to me at awards shows and say something and walk away, and I would think, 'Are we friends, or did she just give me the harshest insult of my life?'"