Charli XCX passed out in Katy Perry's toilet.

Charli XCX

Charli XCX

The 'Boom Clap' hitmaker found herself a little worse for wear at a barbecue at the 'Roar' hitmaker's mansion last year.

She said: "I passed out in her toilet. I'd been out the night before because we'd finished a video shoot and I rolled straight to this barbecue and it was a bit of a nightmare. I had one drink and was like: 'Oh god, game over!'"

When asked if the 30-year-old star found her in the bathroom, she added: "No, thank god, but she did say to me: 'You looked really terrible earlier.'

"I was like: 'Thanks. You can count on me, Katy.' It's fair to say I made a great, solid impression."

Despite not offering Katy a great first impression, the 22-year-old singer was invited to join the 'Dark Horse' hitmaker on tour and the pair have since formed a great friendship.

She shared: "I really like Katy, we've got on really well. She has an incredible eye for over-the-top props, which I really respect. She's really fun."

And it's not just Katy that Charli has a very unforgettable first meeting with as the 'Break The Rules' singer revealed she had an interesting first encounter with Rita Ora.

She told Fabulous magazine: "I'd seen her boobs within the first three seconds of meeting her. We met through Iggy [Azalea], who was doing a show in LA. Rita was singing on 'Black Widow', I was performing Fancy and we were in the same dressing room. She has pretty awesome boobs!

"We crashed a house party in Chicago together once. It was snowing and we rolled up in these two SUVs [like] total morons, got out and were like: 'Yeah! We're here!' We went into the kitchen and began raving to Dizzee Rascal."