They’re not officially called pre-Met Gala parties , but as designers and celebrities start to congregate in New York ahead of the big event on Monday, the social scene responds accordingly.  On Thursday night a mix of fashion, art and Hollywood gathered at the Guggenheim Museum for Cultured Magazine’s third annual ‘Cult100’ party, cohosted by Valentino. Cultured Magazine editor in chief Sarah Harrelson was joined by the likes of Lena Dunham, Grace Gummer, Keke Palmer, Naomi Watts, Adam Scott, BJ Novak, Natalia Dyer, Lisa Rinna, Jake Shane, Tory Burch , Natasha Lyonne, Raul Lopez, Jake Shane, Anna Van Patten, Diana Silvers, Aquaria, Ludovic de Saint Sernin, Francesca Scorsese, Terrence O’Connor, Chris Black, Richie Shazam and more. Grace Gummer and Naomi Watts Lexie Moreland/WWD Outside the museum, Lyonne was discussing her outfits for the slew of events over the weekend.…