He's made no secret of his dislike for Justin Bieber, and branded the pop megastar a 'piece of s**t' in a controversial tweet back in January.
But Seth Rogen has taken his disdain for the Baby hitmaker to a whole new level by launching a furious rant against the star while appearing on Watch What Happens Live on Wednesday night.
Slamming the troubled youngster as 'obnoxious, ungrateful and insincere', the 32-year-old actor didn't hold back as he hit out at the star for putting other people's lives in danger with his dangerous behaviour.
Speaking to Andy Cohen on a special edition of the chat show in Austin, Texas, for South by Southwest Festival, he said: 'In my opinion, Justin Bieber is a piece of s**t.'
'He seems like he’s obnoxious and ungrateful, insincere, and he puts people’s lives at danger and overall he acts like a piece of s**t.'
The comedian first spoke of his dislike for Bieber following the singer's arrest for drag racing and driving under the influence (DUI) in Miami, Florida, in January.
Weighing in on the situation, he said: 'All jokes aside, Justin Bieber is a piece of s**t.'