Katy Perry and John Mayer are planning to move in together
The `Firework` singer and the renowned womaniser - who have been dating for four months - want to take the next step in their relationship and have been house-hunting in Los Angeles and aim to find a place before Christmas.
A source told The Sun newspaper: "John and Katy have decided to give it a proper go and want to find a place in LA to share.
"But lots of people are willing them to fail. They row a bit and have quite a turbulent up-and-down relationship, despite it only being a few months old.
"Many of her friends are certain it will all end in tears.
"But that`s brought them closer in a way. It`s given them an `us against the world` mentality."
Sources say the couple - who had a brief split in October before getting back together - are smitten with each other and like to spend every moment they can together.
One said: "They are together virtually every day.
"They hang out at John`s place, cooking, watching movies and playing music.
"They take the odd trip away but generally they`re trying to keep it behind closed doors."
Katy - whose 14-month marriage to Russell Brand ended last December - has already introduced John to her parents as she knows the romance is serious.
The source added: "Introducing John to her parents was a huge step for Katy and it proves she`s 100 per cent committed."
John has previously dated Jessica Simpson, Jennifer Aniston and Cameron Diaz.