"I met him a few times," the Neighbors star said of his Canadian countryman. "He's a good example of someone, who you meet, who you think you are going to hate and then you get to hate him ... you meet him and he lives up to every one of your expectations."
Rogen, 32, tweeted last January that Bieber was "a piece of [expletive]," after the singer's reckless-driving arrest in Miami.
Rogen told Stern that he first met Bieber backstage at a talkshow in Germany, where the young singer had asked to meet him. When they did meet in person, according to Rogen, Bieber acted like he didn't care.
"What the [expletive], I don't want to meet you!" Rogen remembered thinking during the encounter. "Don't act all nonplussed to meet me. I didn't want to meet you. I was totally cool with not meeting you."
"I was like, 'He's a little bit of a [expletive]. Whatever," Rogen added.