Mayer plans Aniston birthday proposal?

John Mayer will reportedly ask Jennifer Aniston to marry him on her birthday next month.

According to Star, the rock singer has purchased an expensive custom-made engagement ring for Aniston and will propose when she turns 40 on February 11.

"Money's no object for John," a source is quoted as saying. "He didn't want to buy something that anyone else had, so he sketched it and is having it custom-made."

The couple, who have been in an on-off relationship since last April, will allegedly tie the knot at a Greek Orthodox wedding.

When previously questioned on the subject of marriage, Mayer said: "I think I'd be pretty good at proposing. I'd figure that out. I'd get creative."