The 22-year-old singer performed an intimate set in his Los Angeles home on Thursday (1Sep16) as part of the British radio station’s Live Lounge programme, and was joined by an acoustic guitarist. But fans were left shocked when Justin said “f**k” as his musician got the chords wrong at the start of his track Love Yourself, telling listeners, "He's broken his finger, so he's not usually this terrible."

Taking to Twitter not long after his performance, Justin was quick to explain why he swore.

"I don't usually get nervous but tonight I was thrown off and I was. Sorry about that. Really wanted to be my best. Hope u (sic) all had fun," he posted.

His followers immediately jumped in to reassure him after his blunder, with many telling him not to worry and that they’ll always be there for him.

“Just want to make people smile. And teach them the perfect squat,” Justin joked in a follow-up tweet.

Justin’s mishap comes after he was slammed for lip-syncing during his V Festival set in the U.K. in August (20-21Aug16). It was his first time headlining the annual event, though crowds seemed less than impressed after they accused him of miming and “lacking energy” during his set at Hylands Park in Chelmsford on Saturday (20Aug16).

There seemed to be a reason for the heartthrob’s unenthusiastic show though, as he told the audience: “I'm a little hungover, I'm not gonna lie. You guys don't like to fake anything in the U.K., which I respect.” The singer had partied with Rihanna at a London club until the early hours.

However, one Twitter user called @zoelouisesmithx complained: “Nah @justinbieber is miming at V Fest. I ain't (sic) paid £80 for a ticket to his tour to listen to his CD and see him run around the stage,” followed by a middle finger emoji.