Charming is probably not a word most people would use to describe a legal argument. But Sean Mirski’s was just that, when he set out to persuade Courtney Stone, in 2018, that she should forego her inclination to eschew booze for the month of January. He wanted her instead to have a glass of red wine with him on one of their early dates.

“He was like no, no, no, no, no,” she said. “He shows up to the date and said, ‘I have a three-prong argument for why not.’”

He made his case, prominently citing the 21st amendment, which repealed prohibition, and then brandished a pocket-size version of the constitution that Supreme Court Justice Samuel A. Alito Jr., for whom Mr. Mirski was then a law clerk, had signed right next to that very amendment.

“That was a pretty great moment, when I knew I liked him,” she said.

The two met through the dating app Hinge in November 2017, and had dates at a whiskey bar and ice skating in the National Sculpture Garden in Washington. He had graduated with general honors and received a master’s degree in international relations, also with honors, from the University of Chicago, and had received a law degree magna cum laude from Harvard. She was then a pediatric nurse practitioner at Children’s National Medical Center in Washington. She graduated from the University of Maryland and received a master’s degree in nursing from Johns Hopkins University.

“She was super, very down-to-earth, kind, friendly — this would come out even more in subsequent dates — but an incredibly empathetic human being, and that’s not something that always comes out immediately,” he said. “Even on a first date, you could sort of tell she was very smart, very interested, incredibly easy to connect with.”

After their second date, he walked her home, and the two shared their first kiss. “I was a little awkward because my doorman was right there,” Ms. Stone said.

By the time they got to Mr. Mirski’s unfurling of his persuasive skills, she was hooked. Not too long afterward, she knew she was ready to spend the rest of her life with him when the two came home after a winter run in Rock Creek Park in Washington, and though both were chilled, he sent her into the shower first and had a cup of hot chocolate waiting for her when she emerged.

“It seems not a big moment to someone else, but it was to me,” she said. “It was really thoughtful.”

Ms. Stone secretly harbored the ambition of becoming a lawyer herself, and Mr. Mirski, who is a litigation associate for appellate and national security law cases at Arnold & Porter, came across her LSAT study books after they had moved in together. She was thrilled to find that he supported her.

“He immediately was like, ‘I think you were born to do this — we’ll figure out how to pay for it,’” said Ms. Stone, who is now a second-year law student at Georgetown.

The couple married Sept. 25 at the Supreme Court Building in Washington, with Justice Alito officiating. They had originally planned to marry in November, but moved their date up because of the coronavirus. They are to have a renewal of vows or a big party on Sept. 25, 2021.

Mr. Mirski said that the realization that he and Ms. Stone, who will take her husband’s name, would have a future came to him gradually.

“Courtney moved into my apartment in May or June after we first met, because her lease was up, and at that point we started spending a lot more time together,” he said. “You realized that if you can do that and it’s totally natural, there’s no reason not to keep doing that for the rest of your life.”