Sienna Miller reportedly wanted to keep her relationship with Rhys Ifans private because she was embarrassed by his appearance.

The couple have been rumoured to be an item since they were spotted holidaying together in Ibiza over the summer but despite endless pictures of them together, Sienna insisted they were just friends until they were spotted kissing while walking her dogs earlier this month.

A source close to the Factory Girl told the Mirror recently: “Their romance has been a big secret for months now. Rhys wanted the world to know but Sienna was keen to play it down - yet she normally flaunts her romances.”

“A small part of her was embarrassed about Rhys because he’s a step down for her in the looks department, even though she says she’s never known a man who loves her so much and understands her so well.”

“He, on the other hand, is besotted. He’s totally in love with her and loves that they are completely inseparable. He can’t believe his luck.”

The source added that while Notting Hill star Rhys tends to “blow everything he earns on going out and drinking”, he would love to settle down: “He just wants to marry her so that this relationship won’t ever end. He’s already asked her to marry him about five times but Sienna just laughs it off.”

“He’s really good with kid. Everyone’s children adore him. He’s happy to look after them for hours while they all go out.”

“And he’s not a flirt - actually he’s pretty shy with women, which accounts for the fact that he falls so hard when he gets into a relationship. He might play the out-of control party man, but under it all he’s a pretty old-fashioned guy.”

“His friends are worried that she’ll break his heart when someone better looking comes along.”