"She's been a friend of mine for a really long time," Miley, 24, told WKTU's Cubby and Carolina Bermudez Tuesday. "We were actually just realizing the other day that next year, we'll have been friends for 10 years. I think that's my friend that I've known the longest. Which is really, really weird!" And, according to the pop princess, "that's like a really long time" in L.A.
Miley and Katy's friendship dates back to 2008.