Seth Rogen really let Justin Bieber have it when Rogen appeared on "Watch What Happens Live" on Wednesday night.
The comedian was appeared on the show to promote his upcoming film "Neighbors" when a viewer asked Rogen about a tweet he wrote (Warning: tweet contains an expletive) in January in which he called Bieber an expletive. The tweet came after Bieber was arrested for a DUI in Miami Beach.
Rogen took the opportunity to repeat his tweet saying, "In my opinion, Justin Bieber is a piece of [expletive]."
"He seems like he's obnoxious and ungrateful and insincere and he puts people's lives at danger with his horrible, horrible behavior," he added.
Bieber's behavior made headlines again on March 10 after video from a recent deposition was released. The deposition is related to a civil assault case that was filed against the singer by a former bodyguard.
In the video, the singer can be seen refusing to answer questions and at one point he gets defensive with a lawyer when the lawyer asks about Selena Gomez.
As for Rogen, the comedian also revealed Kim Kardashian and Kanye West's reaction to the "Bound 2" parody video he did with James Franco called "Bound 3."
"I've seen both Kim and Kanye after that video came out actually and they both think it's really funny," he said when asked by an audience member. "Thank god. I was worried. 'Cause I'm a big Kanye West fan, honestly, like a huge Kanye West fan."
"I saw him in New York," he added. "And the first thing he said, obviously, was like, 'How come' -- he pointed at my wife and he was like, 'How come she wasn't on the motorcycle?'"
Rogen joked, "He's a sweetheart."