Jennifer Aniston's singer boyfriend John Mayer is reportedly planning on presenting the actress with some surprise bling on her birthday.

The former Friends star hits the big 4-0 on Febraury 11 and might be having a double celebration if new engagement reports are anything to go by.

John is said to be planning on popping the question with a custom-made ring designed by none other than himself.

A source tells Star magazine, "Money's no object for John."

"He didn't want to buy something that anyone else had, so he sketched it and is having it custom-made."

It's claimed that Jen is eager to take their relationship to the next level and has her heart set on a Greek Orthodox wedding.

It seems her wishes may be about to come true...

See Johnnifer's winter wonderland below