Seth Rogen slams Justin Bieber, calls him "obnoxious and "ungrateful"

Seth Rogen slammed Justin Bieber during an episode of Bravo's "Watch What Happens Live" on Wednesday night, calling him "obnoxious" and "ungrateful."

Rogen's omments follow a January tweet in which he bashed the Canadian pop star in the midst of his legal troubles.

Then, while chatting with host Andy Cohen this week, Rogen said, "Justin Bieber is a piece of s---," adding, "He's obnoxious, he's ungrateful, he's insincere."

He added, "He puts people's lives in danger" in reference to his recent DUI arrest.