Mehrnaz Haji-Momenian and Gregory Millwater were married June 13 at Holy Trinity Catholic Church before more than 200 guests. (Moshe Zusman Photography Studio)

Mehrnaz Haji-Momenian always thought she would marry her high school sweetheart. The only problem? She never had one.

Born in Tehran and raised in Washington, Mehrnaz went through four years at Georgetown Visitation Preparatory, four years at the University of Virginia and four years studying medicine at Eastern Virginia Medical School, but she never met the right guy. She had one relationship in her undergraduate years that she describes as toxic.

In 2011, while she was a medical resident, Mehrnaz decided to test her luck at online dating. She tried Match.com but found that the people she interacted with were too eager to rush into a relationship. Next, she tried OkCupid.

“I wanted a relationship, but I found the people on Match to be too serious, and the people on OkCupid weren’t serious enough,” says Mehrnaz, a cardiology hospitalist in Washington.

But in May 2012, Mehrnaz was struck by the OkCupid profile of a local man — whom she found quite handsome — and decided to message him. By that time, Mehrnaz says, she had worked out what she calls the “perfect system” for online dating.

“I was so tired of people sending these three paragraphs about them, and I was like, ‘I don’t care about that,’ ” she says. “Here’s one line: ‘Are you interested in seeing me or not?’ ”

Her first message to Gregory Millwater, a Kensington native and commercial real estate broker, was brief. It read:

“Hi There,

How’s it going?

TGIF :)”

Gregory saw the message, but it took him six months to respond.

“I hear about that to this day,” Gregory, 33, says with a laugh. “There was someone I was kind of dating for a little while there through that summer, and, I don’t know, I just remember being at work one Friday [and] I was just going back through [my messages]. Her message was very minimalistic.”

Gregory read Mehrnaz’s message, but it was her profile that impressed him. She had detailed some of her seemingly contradictory personality traits: “I’m a cynical-optimist, a calm-firecracker, and an artsy-scientist. I try to seek balance in my life, and so I find myself never only one thing . . . without the other.”

Intrigued, Gregory finally messaged back, and the pair began corresponding, bonding over their love of the 1980s and the fact that they had attended sister/brother schools — Georgetown Visitation and Gonzaga College High School. It wasn’t long before they were going on their first date — to Cities Restaurant and Lounge on 19th Street — and discovered they had both attended Visitation’s prom in 2000, one of the many times they believe they might have crossed paths during their school years. Had Mehrnaz narrowly missed her chance to snag a high school sweetheart?

Things progressed from there, and after about 10 dates, Mehrnaz and Gregory got serious.

After dating for about two years, there was a defining, yet brief, point in their relationship. Mehrnaz and Gregory had a fight over taking the next step in their relationship, a disagreement that resulted in them separating for what they say was only a few hours but felt much longer.

“Life was very frustrating,” says Mehrnaz, 33, “because I had moved and things weren’t clicking for my work and my living situation.” She had given up her Arlington apartment, which was too expensive for a place in which she barely spent any time, and moved in with her parents in Great Falls. “I kind of needed an answer, and he wasn’t answering,” she says. “So I said, ‘Well, goodbye.’ ”

“It was a very lonely few hours and the final reality check for me,” Gregory says. “It was real. It was very real. I ended up going and picking up an ‘M’ ring [for Mehrnaz], and I picked up a second ‘M’ ring [for Millwater] and showed up at her parents’ house ready to undo what I had done.”

They decided that day in September 2014 that they were ready to move forward. Mehrnaz wore the two rings until they could visit New York’s Diamond District to find the perfect engagement ring.

There was no more time for “what ifs,” Gregory says.

Then, about a month later, they made it official. On a Friday night, Greg and Mehrnaz headed back to Cities. They sat at the bar outside and read from their first e-mail exchange. Then Gregory proposed and Mehrnaz said yes. They followed up with dinner at 1789, their favorite restaurant in Georgetown, across the street from the site of their future wedding.

Surrounded by shades of pink, gold, pearl and white, Mehrnaz and Gregory were married June 13 at Holy Trinity Catholic Church before more than 200 guests. They had two ceremonies — one Catholic and one Persian, in a nod to Mehrnaz’s heritage.

“It’s strange because I’ve grown up in the U.S. for so long. . . . I haven’t done a lot of true Persian or Iranian things, but [having a Persian ceremony] was really important to my mom,” says Mehrnaz, whose family moved from Tehran to Canada and then the United States when she was 7 years old. “More and more, I kind of reconnected with my Persian side, and even my father-daughter dance was a Persian song.”

The tune was “Ye Dokhtar Daram,” a song from the point of view of a father who believes he has a priceless daughter, a daughter he wouldn’t give to anyone, not even a prince. Gregory, who danced with his mother to Whitney Houston’s “Greatest Love of All,” says the whole day was “a beautiful balance of cultures.”

The day after their wedding, the two traveled to Charlottesville, Va., and spent three days at Boar’s Head Inn. In August, they will travel to Europe for an extended honeymoon.

“I always wanted to marry my high school sweetheart, and in a way I kind of did,” Mehrnaz says. “I remember being in high school and thinking, ‘Oh, I wish I had a boyfriend,’ and in a way he kind of is my high school sweetheart, except I never met him.”