It was wedding celebration time for Hollywood couple Ashton Kutcher and Mila Kunis. And it's not what you're thinking: Kutcher joined Kunis to attend her brother's wedding.

According to a report in People, Michael Kunis, 36, tied the knot with ballet dancer Alexandra Blacker, 29, at the Cathedral Church of Saint Peter. Blacker trained Mila to play a ballerina in 2010's Black Swan. The couple got engaged in December 2012 in San Diego.

Mila wore a blush, knee-length dress for the ceremony which was followed by a reception held at the historic St Petersburg Yacht Club.

As per a source, That '70s Show star couple, Mila and Ashton gifted a 10-day trip to Australia to the newlyweds as a wedding gift.

Following Kutcher's divorce from Demi Moore getting finalised, the Two and a Half Men star hopes to walk down the aisle with the Ted actress. They have known each other for the longest time having formed a thick bond through the shooting of That '70s Show, the American television period sitcom that originally aired on Fox from 23 August, 1998, to 18 May, 2006.

"Ashton and Mila have talked about getting married for quite a while," a business source close to Kutcher told People.

"They're incredibly happy together," adds another friend of Kutcher.

After numerous paparazzi revelations of the couple being spotted wining and dining, and several moments of PDA from Central Park to Saint-Tropez, marriage does seem like the way forward for their globe-trotting romance. The only hindrance earlier was Kutcher's pending divorce from Demi Moore but now with that sorted, maybe an official announcement is on the cards.

"Ashton and Mila have talked about getting engaged and married for quite awhile. He wants to get engaged during the holidays," a business source close to Kutcher told People.