Back in 1983, two musical legends—Paul McCartney and Michael Jackson—came together to duet on their co-written song "Say, Say, Say." Now, more than 30 years later, their daughters are coming together in the name of fashion. On Tuesday evening, Stella McCartney, a beloved fashion designer in her own right, thew one of her famous, celeb-packed pre-collection parties. Among the A-listers on the guest list—in addition to Katy Perry, Amy Poehler, Rashida Jones, St. Vincent, Ava Philippe, Kate Hudson, and so on—was Paris Jackson, who freaked out over meeting her father's onetime collaborator. Also this week, Kendall Jenner headed to Europe for the menswear collections—specifically, her latest gig as the face of Tod's—while Bella Hadid stopped by the Heron Preston presentation. Here, the best party pictures from the week that was.