Though she recently turned 18, Miley Cyrus isn't exactly acting like an adult.
In a video obtained by TMZ, the "Forgiveness and Love" singer is seen smoking out of a bong during a party at her L.A.-area home on November 28.
"Okay, I'm about to lose it now," Cyrus says after taking her first hit. "I'm having a little bit of a trip right now."
According to TMZ sources, the smoke inside the bong is a natural -- and legal -- herb called salvia, which has psychedelic qualities. (Possession of salvia is legal in California.)
With Bush music blaring in the background, the Last Song actress then mistakenly identifies one of the party's guests as her boyfriend, Liam Hemsworth.
"Oh my God! He looks so much like him! He looks so much like Liam," Cyrus giggles. Unable to convince her pal, she asks, "Is that me tripping? He doesn't look like Liam at all? Dude, that looks just like Liam!"
The video was likely copied or stolen from Cyrus' friend's camera, TMZ adds.