AceShowbiz - Katy Perry suffers from obsessive-compulsive disorder (OCD) - and often "freaks out" over tiny problems. The "I Kissed a Girl" hitmaker admits she has the condition, which can cause sufferers to become upset when their routine is disturbed.

Perry's OCD is at its worst when she is on tour - and even a small problem like cat hairs on her clothes can cause her to throw a tantrum. She tells Q magazine, "I certainly have an OCD side when I'm on tour... What are my areas of OCD? Well, if there's broken make-up in my purse I freak out. Also if I am around household pets and some of their fur comes off on my cardigan, then I can get pretty sharp."

"But my worst one is if I see a pair of sunglasses with fingerprints on them. Truly, I cannot stand it. I go ape. 'Oh my God, I can't breathe! Wipe them clean! Agghhh!' "

In another news, Katy Perry made a splash in Singapore on Monday, August 2 by hosting a press conference in a swimming pool - forcing reporters to take notes while waist-deep in water. The pop star stripped to a bikini and perched on a sunlounger on the edge of the infinity pool on the roof of the Marina Bay Hotel to talk about the Singfest 2010 music festival.

Journalists attending the event were asked to strip off and dive into the pool, with many holding tape recorders in the air as they floated in the water surrounded by inflatable toys.