We may earn commission on some of the items you choose to buy. It’s the season of summer galas, and Katie Holmes is showing all of East Hampton how to dress for such. Attending Guild Hall’s celebration on August 7 with her boyfriend, artist Jason Yarmosky, the actor wore a long white gown perfect for the occasion. Sonia Moskowitz // Getty Images FFORMEWith its distinct diamond-pattern pintuck quilting, the crinkled Napa-leather accessory was recognizable as an offering from Tory Burch’s Fleming line. Next to her, Yarmosky smiled in an all-black look, composed of a crewneck sweater and trousers.