It's very unusual for A-listers to take each other to task in public.
There's an unwritten law that the residents of the red carpet do what they can to get along together in the crowded hot house of Hollywood, dodge direct questions when asked about each other's foibles and, whenever the occasion presents itself, gush frantically about each other's talents.
Don't be fooled by the grin, Seth Rogen's not feeling charitable about one particular star
Well, it looks like 'Bad Neighbours' star Seth Rogen didn't get the memo, judging by his recent remarks about teeny-totter Justin Bieber.
Not only did Seth admit to quite a strong dislike while chatting to Howard Stern on his nationwide radio show, but Seth - with whom you'd normally associate gurgly-voiced bonhomie for all men - took the opportunity to break down his contempt into neat chunks on which we could all digest...
WATCH the video above for more... and let us know, do you think Seth's being a tad harsh?
Look... what is there not to like?