"#sadkitty," she captioned the snap.
Cyrus' friend, Katy Weaver, got a tiny heart on her own lip, and captioned an Instagram photo, "We got tattoos on our lips... What the f***.... @mileycyrus #lovemoneyparty."
Here's a closer look:
Inner lip tattoos fade quickly, and usually disappear within a few years.
It must have been a painful experience. The 21-year-old singer shared a photo of herself on Friday with a washcloth over her face.
"My life right now thanks to @waynecoyne @stevendrozd @katy_weaver," Cyrus wrote. "#OUCHYBOOBOO."
2014: The Year in Music [PHOTOS]