Sienna Miller Want to know what Sienna Miller's discovered recently?

Well, it's the very thing that puts a smile on her dial.

But does it have to do something with Rhys Ifans?

She's nattered about all things love, Rhys and Keira Knightley in the latest issue of Elle, which features her on the cover.

She told the magazine: "The big thing I've discovered, the big secret, is that it's all about how happy you are.

"People forget your flaws and imperfections if they see you're happy."

She's recently been filming The Edge of Love alongside Keira, and had to put on a few pounds for the character.

She revealed: "Then I had to face seeing myself alongside Keira, who is the most beautiful woman in the world."

She also told how her and Keira would "sit there and moan to each other and then after a few hours I'd burst out laughing because, ultimately, we both love our jobs and are incredibly privileged to have these lives".

On the boho label often subscribed to her style and appearance she told the magazine: "I hated the 'boho' tag.

"I was either known for being Jude's girlfriend or wearing my mum's old skirts. I rebelled by cutting off my hair and wearing freaky clothes for a while."

Fair enough.

Now, are she and Rhys actually engaged or not?

She said: "See, no ring.

"It's so embarrassing when those stories come out and that your relationship has been somehow fast-forwarded.

"We both had our mums on the phone. It's just awkward. But I'm so happy with our relationship."