Bieber, 19, came under fire after media reports said he urinated in a restaurant mop bucket, cursed at a photo of former U.S. President Bill Clinton in a video, frequently fights with his neighbors and photographers, and failed to pay a fee at an indoor parachuting facility.
"I told Justin to take a bit of time out and people aren't so obsessed with you and nitpick," the New York Post quoted Cyrus, 20, as saying.
"When you're not around, all they want is your music. They want to see what the next thing is. But when your music is out they just want to talk [expletive] about you. When you're a worldwide star, everyone sees everything. Lots of people make a video and put it on Instagram. Some people might think it's funny, but because it's Justin Bieber, it's really bad."