Poor Mary-Kate and Ashley Olsen have been getting a bad rep lately for famously not joining “Fuller House." Lest you think the reasoning behind that disappointing decision is because they’re now uber serious artists who’ve lost their sense of humor, rest assured these girls are still just as fun as ever.

The twins proved that this past weekend with a joint 29th birthday bash in the Hamptons that they dubbed the Olsen Olympics. Friends and family were divided into two teams — the blue Team Ashley and the red Team Mary-Kate.

Forgoing their fave black attire, the twins and their guests donned casual team T-shirts that we can only assume the acclaimed fashion designers made themselves. Not exactly the attire you’d expect from recent CFDA Womenswear Designer of the Year award winners, but MK&A clearly had a blast taking it back to camp, “It Takes Two” style.

Judging by pics from the sporty soiree, it looks the outdoor competition — which Team Ashley reportedly dominated — boasted an obstacle course, a dunk tank, and more.

No word on whether one of the challenges included a chocolate sauce and whip cream slide, à la “So Little Time,” but maybe they’re saving that for their big 3-0 next year.