As if this blindingly sunny NYC day wasn’t enough to remind you that yes, spring is finally here, last night’s park-themed soiree celebrating Stella McCartney‘s newest (and first) shop in Saks Fifth Avenue seemed to drive the point home. Amidst a cotton candy machine and swings, Stella-clad models mingled with guests on the astro-turfed floor, their bouquets of white and silver balloons bobbing well above the crowd’s heads. And we have to say, we can’t think of a more fitting way to showcase McCartney’s playful motifs this season, from the confetti-like sheer dresses to the oversized, juicy-looking fruit prints.

But while the mood was festive, both McCartney and co-host Liv Tyler turned serious when asked about the Costume Institute’s McQueen exhibit at the Met: “The exhibition is exquisite,” said McCartney “He was a good friend of mine for a long time.” Tyler said. “[So the event] was very sad, but also very beautiful.” She added, with a thoughtful laugh, “He would have thought that night was so, so amazing.”

Still, it was hard to be somber on such a celebratory night. “I’m very excited about the store,” said McCartney. “I think it looks pretty great.” Fittingly, the party benefited the Naked Heart Foundation, a charity started by supermodel mom Natalie Vodianova, which helps to build safe and inspiring play environments for children in Russia. “It’s so important to play,” said designer McCartney of the charity. “People forget in countries where playgrounds are readily available. But having those environments is not just important for the children, it brings parents and whole communities together.” And on that note, we’re going outside.