Sophie is Jamie's BFG (Big Friendly Girlfriend)

Since becoming a couple, Sophie Dahl and Jamie Cullum have gone to some lengths to avoid being photographed together.

And this, the first picture of them side by side, may explain why.

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The jazz pianist is reportedly seven inches shorter than his model-turned-author girlfriend, making him little more than 5ft 4in against her 6ft.

Miss Dahl, who was five when her grandfather Roald named the character of Sophie after her in his 1982 book The BFG (Big Friendly Giant), has been seeing Cullum for two months.

Yet despite being seen together on holiday and at parties, they always seemed to be darting off in different directions when cameras were poised.

But there was little for 27-year-old Cullum to hide behind - apart from Miss Dahl of course - when they were snapped taking a cigarette break outside a London restaurant at the weekend.

Friends say 29-year-old Miss Dahl and Cullum, who met at a charity fund-raising event, are looking to make a lasting commitment to one another.

Proof of the romance's seriousness is that Cullum was introduced to her father, actor Julian Holloway, when they were in Los Angeles a couple of weeks ago.

And soon, it is said, Miss Dahl will be joining the Cullum family at their £1.5million Georgian home outside Bath.