Private-equity party boy Marc Leder is billing his stay on St. Barts this week as “Event Week 2011/2012,” according to a rundown of Leder’s parties that’s floating around the island. The Sun Capital Partners honcho has hired party planner Amir Benesh to set up day-and-night bacchanals at his beachfront estate, including one tomorrow touted as the “Famous BBQ Pool Party.” Benesh runs Models-Promo.com, which, its Web site says, offers models, cocktail waitresses, DJs and even fire dancers for shindigs. Rap mogul Russell Simmons attended Leder’s welcome bash Monday with his girlfriend, Australian actress Melissa George. And Simmons’ ex-wife, Kimora Lee, and her husband, Djimon Hounsou, also attended the party. But, spies say, the party was “tame” for Leder, whose wild end-of-summer bash was the talk of the Hamptons this year. At the Bridgehampton home that Leder rented for a whopping $500,000 a month, guests cavorted nude in a pool and performed sex acts, while scantily clad Russian women danced on platforms. Dancers at the party also twirled flaming torches to booming beats. No wonder Leder’s “Cocktail & Dinner Party With Live Show” last night on St. Barts inspired such high expectations. Sources say Leder, said to be worth $400 million, has been on a partying jag since his wife of 22 years, Lisa, cheated on him with a 23-year-old tennis instructor in 2009. A rep for Leder didn’t get back to us.