At first the evening of Aug. 8 unfolded just as Rick Marin had envisioned: After a romantic champagne picnic on the beach at Shelter Island, N.Y., he proposed to fellow writer Ilene Rosenzweig and received an ecstatic yes. And then, he says, "she was dancing on the sand, and I said, 'You still have the ring, right?' She looked at me and said, 'Uh-oh.' " Twelve hours later (with the help of police and metal detectors) the ring, in Marin's family for four generations, was out of the sand and firmly back on Rosenzweig's finger. "Now," Marin says, "if anyone asks me to write a story about crazy engagements, I have one."

At the moment, however, he's busy sharing other, less romantic stories. In his new memoir, Cad: Confessions of a Toxic Bachelor, Marin, 40, a former New York Times reporter, recounts his seven years as a Manhattan single, using the failure of his first marriage as a pickup line and practically pushing women out the door after sleeping with them. "Don't forget your shawl," he tells one conquest who wants to stay the night.

Nonetheless his approach worked (his book details more than a dozen hookups and breakups)—a fact more notable given that Marin, in the words of ex-lover Sandy Fernandez, writing for Salon.com, "looks like Bart's glasses-wearing, asthmatic friend Milhouse from The Simpsons." Even Rosenzweig says she initially resisted dating him because "I thought he was sort of square."

Rosenzweig, 38, would know. As coauthor (with her best friend, designer Cynthia Rowley) of 1999's bestseller Swell: A Girl's Guide to the Good Life, she created a blueprint for women who want to go through life with, in the book's words, "a little swagger and a lot of grace." It has tips on everything from throwing a last-minute dinner party to tipping a handyman. The formula has proven so irresistible that Rosenzweig and Rowley launched a whimsical line of Swell clothing, bedding and accessories at Target and are developing a sitcom for ABC.

The oldest of three siblings raised in Port Washington, N.Y., by Alan, 62, a legal recruiter, and ex-wife Joy Zuckerman, 60, a yoga teacher, Rosenzweig was an editor at Allure magazine in 1996 when she hired Marin to write a celebrity profile. The only child of the late Diego Marin, a Spanish literature professor at the University of Toronto, and Frances, 78, a retired high school language teacher, Marin was on the "dating tear" he began after the 1990 end of his three-year marriage to a woman he calls Elizabeth in Cad. Serial dating, he says, "was a way to shore up my ego."

After his father's 1997 death, Marin reconsidered his nightlife habits. "I needed something heavy like that," he says, "to make me able to commit to one person." Having become friendly with Rosenzweig, Marin found himself falling for her quirky side, which included dragging him to a trapeze class and taking him bobsledding at upstate Lake Placid. "She would always say or do something unexpected," says Marin, who worked hard to reciprocate. "He would ask me on all these special dates," Rosenzweig recalls, like screenings of Rat Pack films or fashion parties. "He just always knew where I wanted to be."

Today Marin and Rosenzweig—who are "a dynamic duo," says pal Rowley—share a one-bedroom Manhattan apartment and a ranch house in Sag Harbor, N.Y. Their May wedding, however, will take place in a 13th-century monastery in Portofino, Italy, where life moves at a decidedly slower pace. "If it was in New York," says Rosenzweig, "I would be stressing over cherry tomato canapés and tuna tartare. But over there it's so beautiful you don't have to worry about anything else!"

Galina Espinoza
Rebecca Paley and Fannie Weinstein in New York City

  • Contributors:
  • Rebecca Paley,
  • Fannie Weinstein.