There are so many impersonal parties out there—at stores, at nightclubs, at former gas stations that have been turned into public-art installations—that it is just nice when someone opens her home to celebrate whatever it is that she wants to celebrate.

On Tuesday, the playwright, novelist and television writer Theresa Rebeck hosted a fundraising dinner for the writers organization Pen America at her home in Brooklyn. (This year’s Pen literary awards, honoring, among others, Katherine Boo and Larry Kramer, will take place on Monday at the CUNY Graduate Center.)

Ms. Rebeck’s guests included the novelist Elinor Lipman; the playwright Marsha Norman; Tim Sanford, the artistic director of Playwrights Horizons; and Meg Wolitzer, whom the evening was celebrating. Ms. Wolitzer read briefly from her best-selling book “The Interestings,” about the lives of a group of friends who meet at an artsy summer camp (emphasis on “briefly”).

“It’ll sort of be like those children’s versions of classic literature,” Ms. Wolitzer said, referencing abridged Tolstoy. “You know, ‘All happy families are alike, but Anna Karenina’s family was different. And, wow, she got hit by a train.’”

Ms. Wolitzer asked how many people in Ms. Rebeck’s living room had been at summer camp. Nearly everyone raised a hand.

“You go anywhere out of New York, and only one person raises their hands,” Ms. Wolitzer said. “Then I usually say, ‘This book isn’t about summer camp. It’s about getting older and disappointment. Who’s experienced that?’ And then all the hands go up.”

Ms. Rebeck and Ms. Wolitzer also described the book, in which one character becomes far more successful—both artistically and financially—than all the others, as being about “quiet envy.”

Quiet envy—or even envy of the relatively loud variety—was, no doubt, a particularly rampant emotion earlier in the evening at a party for the Key to the Cure campaign at the gorgeous, art-filled, Park Avenue home of Jamie Tisch.

“Wait,” said the fashion designer Dennis Basso. “She has a DJ in her living room?” (It was just for the night, and it was Harley Viera Newton.)

Ms. Tisch was celebrating the longtime partnership of the Entertainment Industry Foundation’s (EIF) Women’s Cancer Research Fund (WCRF) with Saks Fifth Avenue. (She is a co-founder of the WCRF.) Each year, the department store partners with a celebrity and a fashion designer to create a T-shirt, with proceeds going to WCRF. This year the celebrity is Jennifer Aniston and the designer is Peter Dundas of Pucci.

In the last few years, Ms. Tisch has moved from Los Angeles to New York, and, she said, “we’ve never had a chance for our new friends here to mix with our old friends. It felt like an appropriate time and place. We didn’t want to have a large event.”

Among the “interestings” at this party were Tamara Mellon; Steve Sadove of Saks; Elizabeth Lindemann; Coralie Charriol; the R&B singer Ciara; and the football-player-turned-talk-show-host Michael Strahan, who, we told him, is inescapable on Taxi TV.

“Every time I get in a taxi, I turn it off,” Mr. Strahan said.

Of course the cause was a good one, but we couldn’t tell if Mr. Strahan was disappointed or not that there wouldn’t be a Key to the Cure T-shirt available in his size. The shirts, which sell for $35 at Saks, are only available for the ladies.

“It wouldn’t fit me either,” Mr. Sadove said. “Remember that 85% of our business is women.”

“If you gave me a large, that’s not going to work for me,” he said. “I need a XXL.”

“We’ll stitch four of them together for you,” Mr. Dundas said.

Mr. Dundas conceded that even if it didn’t quite fit, he might wear one of his women’s Key to the Cure shirts. “I’ve been known to wear things that are quite tight,” he said. How interesting: a fashion designer living on the edge. He had only one night in New York before heading back to Europe. What would he do?

“All of the things that I’m not supposed to be doing,” he said. “And that I can’t do in Paris.”