Jennifer Aniston and John Mayer are reportedly set to put their three-month relationship to the test with a "trial marriage".

Despite the recent spate of marriage rumours, the couple are said to be taking things more slowly - starting with moving in together.

"John wants to settle down as much as Jennifer does,” says a source.

"What's more, he's been telling her that he thinks she is the one and she believes him."

John is expected to move into Jennifer's Beverly Hills pad when he finishes touring in September.

The insider adds that babies are also likely to be part of the couple's future.

"John is the first guy since Brad who has talked seriously about having children and Jennifer is very excited about it," the source tells Grazia.

Click to see Jen's homage to beige in our Jennifer Aniston Style gallery