Justin Bieber Says He Had to "Vent" About Birthday, but Plans to "Chill" Ahead of London Shows

Crooner says he's gonna relax with friends after the debacle that was his 19th B-day celebration

Justin Bieber had to get something off his (bare) chest.

And no, it wasn't responding to Olivia Wilde's call to put his "f--king shirt on."

The "Boyfriend" singer is explaining why he felt the need to post a note to Instagram yesterday slamming London's Cirque du Soir nightclub for shutting down his birthday bash on Friday night, what he subsequently called his "worst birthday" ever. 

"Sometimes u just wanna vent and not be quiet. I love my fans though. Just gonna chill with friends. London shows this week," he tweeted.

In his Instagram declaration discussing the purported confrontation Bieber's entourage got into with Cirque's security, J.B. dismissed the hot spot's claim that his camp had tried to sneak people under the age of 18 in.

He also clarified that when he tweeted it was his "worst bday," he meant that he was unhappy about "dummies pushing over my fans and being overly aggressive." But he noted he was just "mad in the moment" and is perfectly fine now because his hometown pals had joined him in England to help ring in his 19th birthday.

"It ain't always easy but is what it is," he added. "Gonna stay focused."

Bieber is scheduled to kick off the first of four sold-out shows at London's O2 Arena as part of the European leg of his Believe Tour tonight.