Miley Cyrus -- Get High Like A Butterfly … Sing About My Kitty Parts

Miley Cyrus got her freak on … and freaked out the audience while singing a cover of Khia’s hit song, “My Neck, My Back” during the Adult Swim Upfront Party Wednesday night.

Miley -- who made sure to prep herself properly with a big ol’ blunt -- strutted around the stage in butterfly wings ... and then belted out the awesomely romantic lyrics.

Remember, she's single again ... so, fellas just focus on Miley's neck, her back, her p****, and her crack. Check it out.