They're rarely spotted without the other by their side.
So it's no wonder Mary-Kate and Ashley Olsen both served as bridesmaids for their friend's wedding in New Zealand last week.
The 30-year-old actresses-turned-fashion designers matched looks in chic all-black gowns, according to Daily Mail.
The former Full House stars locked arms as they walked down the aisle in front of Maggie Kayne and Travis Hayden's closest friends and family.
Mary-Kate carried an oil-paper umbrella to shade the sun, while Ashley held a beautiful bouquet of white flowers.