Katy Perry and Orlando Bloom are "hoarders by nature"

She said: "My boyfriend doesn't even know that I threw away his toiletry bag while he's been gone. I told him I got him a new one for Christmas. He said, 'Oh, this has been around the world for 10 years'

and he wanted to keep it in a drawer. I was like, 'The moment you leave is the moment this thing is going in the trash.'"

And the 34-year-old singer says there is a "psychology" behind her need to hoard her possessions.

She explained: "You get something and you're like, 'I'm never going to get it again' or 'I'll never have the means to get it again.' It's this psychology behind it, when all of a sudden you can just purchase something - it's very wild for your brain."

Katy admits to having Obsessive Compulsive Disorder and thinks it stems from her desperately "trying to control her environment" when she was younger.

Speaking to the new issue of Paper magazine, she shared: "I'm very OCD and I don't say that lightly. It was just a product of me trying to control my environment."

Katy had previously revealed "opposites attract" when it comes to her relationship with Orlando.

She confessed: "I think when you're attracted to someone, it's sort of like how opposites attract. I'm looking for that balance and maybe he's looking for [someone who is] a multi-tasker."