'Knocked Up' star Seth Rogen has revealed that following Bieber's arrest he came to the realisation that the 'As Long As You Love Me' heartthrob is just an "obnoxious" teenager. 

During an interview on Bravo's 'Watch What Happens Live', Rogen was asked his opinion on the Canadian superstar and his recent behaviour, to which he replied that the singer is being incredibly irresponsible and "horrible":

"In my opinion, Justin Bieber's a piece of sh--."

Rogen continued: "He seems like he's obnoxious and ungrateful and insincere, and he puts people's lives in danger with his horrible, horrible behaviour."

Bieber recently took to his official Twitter page and told his followers that he's currently focusing on his music: "Studio. Always working. My music is my heart."

Watch Bieber's recent court deposition video here: