When Calvin Klein executives started planning an outdoors party for the second section of the High Line — an after-party to the adjacent, tented Friends of the High Line’s Spring benefit — they couldn’t anticipated the dismal spring the city has had so far. But cold air and a persistent drizzle didn’t stop the revelers, including Edward Norton, Nora Zehetner, André Balazs, Rachel Roy, Swizz Beatz, Eric Trump, Olympia Scarry, Hanneli Mustaparta, Leigh Lezark, Cecilia Dean and Celerie Kemble. They crowded around the heat lamps with co-hosts Italo Zucchelli and Francisco Costa, who had just returned from Cannes where he threw a party on the Croisette. “It’s just as amazing here,” he said. Sky Ferreira, who sang for the occasion, didn’t mind the blustery conditions either. “It makes the performance a lot more dramatic,” she said.