Justin Bieber is, by most accounts, an amiable, respectful 18-year-old -- not a brat, despite his immense fame and privilege. While he may not necessarily love giving interviews (anyone would probably get a little tired of answering the same questions over and over again), he's usually still cordial and professional.

That wasn't the case with one particular radio show. During a call with DJs at Mojo in the Morning, Bieber got so irritated that he hung up on them. What got him so upset? Mentions of Justin Timberlake and One Direction. As host Mojo put it, "We had a fun conversation, and then at the end, it went horribly wrong."

The radio host, Mojo, brought up Timberlake in what did seem like an earnest compliment, telling Bieber that he thought the song 'Boyfriend' was actually by the former NSYNCer, as Biebs' label played the track for him without telling him who the artist was. (A lot of critics agreed, even us!) He even specified, "Please take this as a compliment."

We don't think Mojo meant any harm by that particular comment, but Bieber was audibly irritated, as he's probably heard the comparison a million times already. Bieber smarted, "Man, that's crazy, 'cause our voices sound nothing alike." Mojo tried to explain that it was a similar sound, but Biebs wasn't having it. "I'm not trying to sound like someone else," he said, the impatience evident in his tone. "To say I sound like someone else is not really a compliment. I think if you said, like, 'I hear some Justin Timberlake-esque things in your sound' I would take that as a compliment. But to say you thought it was Justin Timberlake ... " No offense, Beliebers, but while that isn't exactly what Mojo verbalized, we do think that's what he meant.

Bieber clarified that he had nothing against JT and that he has the utmost respect for him as a fellow artist, but that he wants to be known for doing his own thing. Fair enough.

The chat continues pretty innocuously until the conversation turned to U.K. heartthrobs One Direction. When Mojo asks if Bieber and the British boy band are pals, Bieber says that they've hung out and that they're "good kids." So cute!

But then it gets a little ugly. Mojo asks Biebs, "Do you worry about Harry when he's around your mom? Because it seems like he likes older women." Mojo is, of course, referencing Harry Styles' penchant for cougar huntin'. Bieber, who's famously doting and respectful of both his mom and of his girlfriend, Selena Gomez, was taken aback by the question. After some stammering, Bieber replied with a chuckle, "You should worry about me and your mom, bro." Mojo replied that his mom is dead. And then ... click.

Bieber's rep tried calling him back and said she thinks Bieber is in an area with poor cell service, then called back and told Mojo, "He got a little upset with the question ... he probably won't be calling back."

Mojo revealed that Biebs' galpal Gomez and Bieber made a joke about Harry being around their moms, which they were referencing later. You can listen to Mojo and his cohosts discuss the incident in the clip below. We think both parties were a little childish in the incident. Do you agree? Sound off in the comments below!

Listen to Justin Bieber's Interview With Mojo