“You mean Sam Taylor-Wood,” Ms. Hanley Mellon said.

Mr. Mellon’s initial foray into fashion was as the creative director of Jimmy Choo’s collection of men’s shoes. After Tamara Mellon, whom he met at an Alcoholics Anonymous meeting in 1997, decided she no longer wanted a men’s line (“She wanted to create the best women’s shoe,” Mr. Mellon said), he founded Harry’s of London, named for his grandfather Harry Stokes, selling dress shoes with sneaker soles. (In 2006, a majority stake in the company was sold to the Richemont Group, the Swiss luxury-goods holding company.)

He jokes that Ms. Hanley Mellon, at 14 years his junior, forgets that he has “had a whole other life before we were married.” That included working in the music industry in Los Angeles for a decade before meeting Tamara Mellon. Although the two divorced almost a decade ago, they remain close enough that she attended the Hanley-Mellons’s wedding in 2010, an elopement of sorts at Diane von Furstenberg’s house on Harbour Island in the Bahamas.

Ms. Hanley Mellon grew up in Greenwich, Conn. After studying at Trinity College, she worked at Ralph Lauren and was a buyer at the Intermix chain of boutiques. She had a short-lived clothing line and boutique, both named Hanley.

The two decided early on in their relationship to collaborate on clothing, but “we moved to California for two years, got married and had two kids,” Ms. Hanley Mellon said. (Force Hanley Mellon, 3, and Olympia Drexel Mellon, 1, were not in the room during the interview. There is also a teacup Yorkie named Tuleh, named for the clothing label where Ms. Hanley Mellon interned.)

The couple started slowly with hanleymellon.com, a lifestyle website that has fashion articles (“For Nicer Weather Days” features a Balenciaga bag, $1,485, and Mulberry coat, $3,000), posts on the perfect crop top featuring portraits of Ms. Hanley Mellon, and collages of images they find inspiring.