Fans upset with Rihanna after late apperances and weak performances!!!!

Rihanna fans in London were pretty upset with the singer for arriving late and giving a performance that wasn't too up to par.

Radar Online reports RiRi has been late to several European concerts lately, but had no problem partying until 3 a.m. with her brother Rorrey, assistant and BFF Melissa Ford, and model friend Cara Delevigne on Sunday -- the night before her concert in Birmingham for which she showed up two hours late.

When Cara left the club, she appeared dazed and had a suspicious white powder splattered across her lap. Cara was also spotted last month dropping a bag of white powder in front of her apartment after another late night out.

On Monday fans were waiting for Ri's scheduled 8 p.m. appearance but Ri didn't find the stage until about 10:30 p.m. -- and apparently it wasn't worth the wait. A reviewer of Sunday night's concert wrote, “Rihanna wasn’t the most vigorous performer, and she looked dead-eyed …Rihanna deserves a break and so do we.”

Rihanna's Diamond's Tour is set to wrap up on November 15 in New Orleans.