The hit NBC comedy series, Saturday Night Live has been a weekly staple since its debut back in 1975! The show has launched the careers of countless comics from Eddie Murphy, Dan Aykroyd, all the way to Bill Hader.

Bill Hader was a cast member and writer on SNL from 2005 to 2013, popularizing his character, Stefon. During Hader's time on the show, the comedian met quite a few celeb hosts and musical guests, however, there have been a few controversial ones.

When Bill and fellow SNL co-star, Jay Pharoah visited Andy Cohen at Watch What Happens Live! the two revealed which host they didn't like working with, and it turns out, we aren't all that shocked.

Related: 10 Major Celebrities Who Started As Writers On 'SNL'

Bill Hader Hated This 'SNL' Musical Guest

Bill Hader has had quite a lot of success after joining the cast of Saturday Night Live back in 2005. While he had an absolutely great 8-year run on the show, it appears as if Bill didn't enjoy one specific guest host and musical act.

Although he and fellow SNL star, Jay Pharoah had a stellar time together on Andy Cohen's late-night talk show, Watch What Happens Live! the two didn't seem to hit it off all that well with one particular pop star.

During their interview with Cohen, a caller inquired about who the "worst-behaved musical guest or host" was, and it didn't take either of them much time to answer!

"It's always the worst!" Hader said, pointing to how viewers always want the juicy gossip. Well, when it comes to worst-behaved musical guests, both Bill and Jay knew the answer.

"We both know, dawg,” Pharoah said. To which Hader made clear it was Justin Bieber, “Yeah, it was [Justin] Bieber,” he told Cohen and the caller. Jay Pharoah quickly chuckled after attempting to keep it a secret before Bill blatantly spilled the Bieber beans.

Related: Why Fans Think Pete Davidson Could Be Leaving ‘SNL’

Justin Bieber appeared as both the gest host and musical act of the night back in February 2013 following the release of his album, Believe, and the start of his notorious "bad boy" phase.

During his on-screen time with Jason Sudeikis, Justin Bieber teased viewers with a few skits the duo filmed for promo, which have garnered a few cringy reviews. Well, it seems as if the promo wasn't the only sour moment with Biebs on SNL.

When Andy Cohen asked Bill Hader why Justin Bieber was the worst-behaved, the Trainwreck actor said that Justin just wasn't in the best spot at the time.

“He was in a bad place,” Hader said. “Maybe he’s in a better place. But back then ... it was rough.” Hader said. "SNL” guests are usually on their best behavior, but Bieber seemed “exhausted or at the end of a rope.”

This wasn't the first time Bill Hader made comments regarding Bieber's 2013 appearance. During an interview with Howard Stern, Hader went on to mock the entourage that Justin had with him, claiming Justin had “a guy holding a slice of pizza, a guy holding a Diet Coke.”

Luckily, there's no bad blood between Justin or SNL, as he made his return back in October 2020 where he performed his hit song, 'Lonely'.

Next: Fan Recalls Hilarious Moment Of Bill Hader Getting Tipsy At LA Restaurant