There's a reason her Instagram handle is "badgalriri."

Rihanna is acting up and misbehaving on the European leg of her Diamonds World Tour, arriving tardy for both shows of her two-night stand in Switzerland. Who does she think she is -- Justin Bieber?

RiRi was 90 minutes late to her Zurich gig on Saturday, June 29 and rumor has it that she was partying her face off on Sunday, June 30, and thus two hours late for that show.

She was skewered by the media, which accused her of lip-synching and singing like a subway busker. Ouch.

After her Saturday show, she resumed partying at a nightclub with her dancers until 3:30AM.

It must've been a rough night, since she showed up for Sunday's show at 10PM, making her several hours late.

Fans issued furious tweets –some of which you can read here.

And you can seen image of the singer partying above. She's not hiding her hedonism.

If there's one thing we can say about Rihanna, she is a hard worker, releasing an album a year, touring and jetsetting across the globe to honor marketing endorsements for her fashion and makeup deals, and to fulfill promotional commitments.

But she parties as hard as she works.

When the partying starts to affect her performances and her fans, there needs to be an intervention on the part of her management, even if it's just a talking to.