Chelsa and Dennis's Fall Wedding in Upstate New York

Dennis Crowley and Chelsa Skees are a thoroughly modern couple: He's a founder of Foursquare; she's a stylist about to launch her own beauty line. But for their first get-together in 2008, the New Yorkers, who had met at a party, agreed on a sweetly old-fashioned activity: bicycling. What they hadn't established? Whether it was a date at all. So when Dennis swooped in for a first kiss, a startled Chelsa, who thought they had just been hanging as friends, quickly pedaled away. Dennis, a little embarrassed but undeterred, texted her later and asked her out again. This time intentions were clear, and the two soon became an item.

Four years later, on a moonlit beach in Costa Rica, Dennis went for romance on bikes again. "I wanted to go back to the hotel," remembers Chelsa, "but he insisted I stop riding." Once she obliged, he popped the question—well, sort of. "He grabbed my hand and just started babbling. I was like, 'huh?'" Once she realized what was happening, "I cried, said yes, and then we both laughed at how his awkward proposal matched our first date perfectly!"

For their wedding 10 months later, on October 19, 2013, at Buttermilk Falls Inn in upstate New York, the fun-loving duo sent invitations by Mélangerie that were in the form of '80s-style viewfinders. Prior to these invitations, the pair had also mailed flip-book save-the-dates. "We're kids at heart," says the bride.

Bridesmaids wore Anthropologie tops and silk Alice + Olivia pants. "I inadvertently dressed my girls to look like me on any given day!" jokes Chelsa.

Swans glided on the water at Buttermilk Falls Inn, a 75-acre estate on the Hudson River, in Milton, New York.

The duo designed the ceremony programs, which featured a bicycle illustration.

Chelsa and Dennis also brought a little throwback flair to their ceremony, officiated by a friend and attended by 170: The bride made her entrance to the theme from Jurassic Park, a childhood favorite. "Everyone told me seeing Chelsa walk down the aisle would be the best part," says Dennis. "It definitely lived up to the hype." As for the bride, she actually doesn't remember hearing any music play, just that they were holding hands and laughing.

Chelsa's nephew, in a Zara cardigan and cap, also carried a "Here Comes the Bride" sign down the aisle.

Chelsa's niece, in a tutu from Etsy, a Zara cardigan, and an ivy crown, served as flower girl.

Gents pinned clusters of bush ivy, black scabiosa, sea oats, and feathers to their lapels.

The bride's bouquet, made by Amy Merrick, combined Boston ferns and wild grasses with ranunculus and parrot tulips.

Dennis in Calvin Klein Collection and Chelsa, wearing Vera Wang, shared a solo moment after their vows. "We didn't want to see each other before the ceremony," she says.

With official business out of the way, the party fired up. Revelers sipped "Squeezey McWhiskeys," the couple's playful name for old-fashioneds, before sitting down to a "Splitty-Split" dinner, the pair's term for family-style meals. (These and other Chelsa-and-Dennis-isms were handily documented in a cheat sheet at each place setting.) Burlap-covered tables were topped with centerpieces of ferns, sheet moss, sea oats, and mushrooms.

A swing band got people moving, Dennis twirled with his mom to Guns N' Roses' "Sweet Child o' Mine," and all of it was documented in true 21st-century style: with the hashtag #SQZ, which stands for "Squeeze," the couple's "admittedly super-annoying" nickname for each another.

"We aren't one of those couples who have a song, so we listened to different artists until we found something that felt right," says Chelsa of their first dance to Sean Hayes's "When We Fall In."

Guests received welcome bags stocked with basics, such as Advil and water, and treats, including custom cookies from Baked on Briar and wine.

The pair took a stroll—and posed for photos—with their beloved bikes, which were decorated with ivy and displayed at the front of the aisle.

Location and Catering: Buttermilk Falls Inn
Event Coordination: Tinsel & Twine
Flowers: Amy Merrick Flowers & Styling
Photography: Shannen Natasha Weddings
Stationery: Flipbooks NY (save-the-dates); Mélangerie NYC (invitations)
Music: The Sultans of Swing
Rentals and Lighting: Unlimited Party Rental
Videography: Shark Pig
Bride's Veil: Satya Twena
Bride's Shoes: Valentino
Hair: Kiersten Johnson
Makeup: Sheri Ciliento
Groom's Accessories: Theory (shirt); YSL (tie)
Announcer Boy Attire: Gap (shirt and pants); Zara (cap and cardigan)
Transportation: West Point Tours
Photo Booth: Wicked Fun Photobooth
Restrooms: Premier Executive Trailers (800-275-3616)
Cookies: Baked on Briar