Nikki Reed has posted a gushing tribute to her husband Ian Somerhalder on his birthday.

The 'Twilight' star posted a sweet message for the 'Vampire Diaries' actor to mark his 39th birthday and revealed the secret to their relationship.

Captioning pictures of the pair on Instagram, she wrote: ''To the only person that loves broccoli and a homemade face mask more than I do... my poet, my dreamer, my favorite guy in the world ... A day celebrating you and only you, nothing makes me happier. Another year, an incredible year, one we will surely never forget ...

''I get it now. The secret to our long happy marriage is this: I need to be in bed by 930, and you need to start manifesting all your dreams at 10. Done. As long as we always find each other for breakfast :) Happy birthday to the best partner and father in the world, 39 looks damn good on you. We love you (sic)''

And the 29-year-old actress - who has four-month-old daughter Bodhi with Ian - loves every little thing about her husband.

She added in the sweet message: ''It's hearing your sweet voice singing silly songs with me in the morning ... It's knowing I can always count on you to order five trays of french fries so I can eat four ... It's driving across the country listening to you tell stories from another life ...

''It's realizing we have not played any music because we always have too much to talk about. It's watching you make the most outrageous faces trying to get a belly laugh out of our tiny one. (sic)''