After twenty years of togetherness and three kids, Woody Harrelson, the former star of hit TV series 'Cheers', finally tied the knot with Laura Louie, his former assistant and long-time girlfriend, in Maui on Sunday.

US Weekly reports, as the two tied the knot, they were watched by an intimate crowd including Owen Wilson, Willie Nelson and Sean Penn, while pal Alanis Morissette sang at the wedding ceremony.

Louie and Harrelson, 47, who reside in Maui, have three daughters - Deni, 15, Zoe, 12, and Makani, 2, referred to as their 'goddess trilogy' since the birth of their youngest - Makani. Blogging about their life on www. voiceyourself. com, a site they co-founded to encourage organic living, Harrelson writes: 'VYS, along with my three daughters, represents the ultimate product of my life's work.'

The actor's second marriage, Harrelson was earlier married to Nancy, playwright Neil Simon's daughter, a marriage that lasted only 10-months.