Pop star Justin Bieber had fans wondering what happened when he tweeted two words early Saturday morning: "Worst birthday."
This simple Twitter message soon spread so widely, it is believed to be the third most retweeted message ever, according to The Atlantic.
So what went wrong?
Only on Feb. 28, the singer had been celebrating so exuberantly that he literally lost his shirt. (After tweeting about having a "great show" in Birmingham, England, Bieber was photographed shirtless with his pants down around his thighs as he returned to his hotel, as Us Weekly reports.) And in the hours leading up to his "Worst birthday" tweet, he had been anticipating such a good time.
"Gonna be fun tonight. Thanks to everyone for all the birthday wishes. 19!" he tweeted, followed later by: "Big night ahead."
Many fans and news outlets have been trying to piece together the events of the evening.
According to The Atlantic, part of the letdown was that turning 19 wasn't quite the expected milestone for Bieber, since he was celebrating in London, where he had already reached the legal drinking age.
Then, there was reportedly an unexplained "incident" between his entourage and security at the nightclub where he was holding a circus-themed party.
Us Weekly reports that the kerfuffle was over Bieber's guest Jaden Smith, the 14-year-old son of actor Will Smith, who was not old enough to be at the club.
"There was never any mention of Jaden being there, so when he showed up, it caused problems," an unnamed source told Us Weekly. "They could have stayed if Jaden left, but Justin wanted to be a good friend."
Wenn.com, however, says Bieber denies bringing in underage guests.
"You think Will [Smith] is letting his 14 year old [son Jaden] in a club, I don't think so," Bieber wrote on Instagram.com, according to Wenn.com. "I love how the club wanted to give the press another reason to why we didn't stay at their weak a** club so they wouldn't look bad for me walking in and right back out."
He reportedly added that his unhappiness was exaggerated: "I said 'worst bday' [on Twitter] but that was due to dummies pushing over my fans and being overly aggressive… it wasn't the worst bday [birthday] cuz all my friends from back home flew in… I was just mad in the moment."
Apparently, the singer is not the only one who overreacts in the moment. His fans get pretty heated too.
According to The Telegraph, a 15-year-old girl posted a message on Twitter several weeks ago, saying, "Not really a fan of Justin Bieber but his acoustic album is actually good!"
After Bieber retweeted the message, his fans responded in jealousy, calling her a "whore" and telling her to "go kill yourself." Surely there are worse things than having a confrontation at a club. What was your worst birthday ever?