Dave, 29, is a software engineer. Rachel, 30, works for the government. They live in Falls Church.

The Main Event: They will join in matrimony in a Catholic ceremony Oct. 13 at the Fort Myer Officers’ Club.

How They Met: OKCupid.

First Date: They met at the Iwo Jima Memorial on July 4 to watch the fireworks.

First Impressions: “He looked so young, especially with his backpack full of snacks and a blanket.”

How He Proposed: He sent her an email from a website (he’d made) called Arlington Treasure Hunt that made it look like she’d win an iPad if she followed emailed clues. At the Iwo Jima Memorial, the final email said, “Rachel, Dave has a question for you.”

Most Stupid Fight: On a tubing trip, they stopped for lunch, and he offered her his Butterfinger. “She said yes. I wasn’t expecting that and didn’t want to actually give it to her.”

Making It Unique: Because of the venue, every guest’s vehicle will be searched upon arrival.

With Infinite Funds: Dave would commission a bear-shaped ice sculpture.a