When it comes to summers out East, the only necessity is a chic swimsuit!

This past weekend, we posted up at cult favorite swimwear brand Andie's new Sag Harbor boutique for an afternoon shopping affair.

Perched just south of the bay in a vine covered home on Main Street, the dreamy store has the perfect looks for a sunny day à la piscine or à la plage. 

Stylish Hamptonites, including Stephanie Nass, Christy Doramus, Heather Anderson, Kelly Brady and more, sipped on a seasonal must, Chandon Rosé Brut, while perusing the New York-based brand's must-have styles. 

Sophisticated one-pieces - like the adjustable snap front Malibu or the ribbed, Grecian-inspired Mykonos, and flirty sets (just trust us and think pink in the Maui top!) - made their way into many a shopping bag. 

Though guests went home with more than just their new favorite suit!

The Hamptons-themed gift bags included a number of other East End essentials - sparkling accessories from Adinas Jewels, Supergoop's SPF Glow Stick, Barrière's It Girl-approved face masks and itch-saving Debug Mode spray, chocolates from La Maison du Chocolat, and lastly, a gift voucher to Tote Taxi, an over-packer's dream service!

Curious to see inside the summer soirée? 

Click through!

[Photos by Cameron Burton for Guest of a Guest]