Mila Kunis and Ashton Kutcher's wedding party was ''very relaxed''.

The couple - who celebrated tying the knot a few months ago with their family and friends at the Secret Garden at Parrish Ranch in Oak Glen, California on July 4 - are said to have been totally at ease as they prepared to mark the occasion with their nearest and dearest.

A source told People magazine: ''They seemed very relaxed. You would have never guessed they were actually preparing for [a big celebration].''

Mila, 31, and Ashton, 37 - who also celebrated with a poolside lunch at their Beverly Hills home on July 2 - are said to have looked totally besotted with each other as they celebrated their private nuptials.

A source said: ''They're so happy. They're so in love.''

Although it was not their official wedding day, the couple treated it as such and both Mila and the couple's eight-month-old daughter, Wyatt, wore white.

In January, the 'Two and a Half Men' star posted a message on his Facebook page which featured the words 'Happy New Year Love The Kutchers' drawn in the sand, fuelling speculation they had wed in secret.

And two months later, Mila, 31, appeared to confirm the news during the first episode of 'The Late Late Show with James Corden'.

The 36-year-old chat show host pressed the 'Ted' actress to speak about her secretive relationship with the 37-year-old actor, asking, ''Either you're married or you're not,'' to which she enigmatically replied: ''Maybe''.

However, the 'Into the Woods' star was not prepared to drop the topic, demanding to see her hand, on which she was wearing a wedding ring.

Announcing the news to the audience, James said: ''They are married, look!''

Following the reveal, Mila - who began dating her former 'That 70s Show' co-star in 2012 - blushed with embarrassment but insisted, ''It's fine'' when asked by the host if he had offended her as the broadcast went to an ad break.