Mary-Kate and Ashley Olsen celebrated their 29th birthday over the weekend, and decided to go all out for the occasion.

Ditching their all-black ensembles for once, the girls threw an incredible Olympics-themed outdoor bash for friends and family at an estate in the Hamptons, and we are LOVING the pictures.

It's certainly not as swanky an affair as we'd usually associate with the superstar sisters, but it looks like one hell of a birthday party.

With a series of outdoor activities from dunk tanks, obstacle courses and even fireworks on hand, friends were split into either Team MK or Team Ashley for the day's events.

Although our invite seems to have gotten lost in the post, partygoers kept us all updated throughout the day, sharing #OlsenOlympics photos via social media – though a number of the original posts were deleted by the end of the evening.

We bet a few of those t-shirts were robbed as souvenirs…

It seems like Ashley's team won out at the end of the day, with the girls' pal Jared Seligman sharing this picture of the victorious birthday girl:

"Champions," he wrote, adding, "#TeamAshley #OlsenOlympics #Twinning #SorryMK."

While a great crowd was on hand to help the girls celebrate, it seems Mary Kate's fiancé, 46-year-old French banker Olivier Sarkozy, had to skip out on proceedings. 

We hope the girls had a great day all the same!