“The Avengers” star Mark Ruffalo confirmed there will be a sequel to the smash hit movie at Patricia Duff’s party for charity The Common Good at Andrea Stark’s Midtown apartment on Thursday. Asked if “The Avengers 2” is in the offing, “He smiled and nodded,” a spy told us. But Ruffalo was more eager to talk about his campaign to ban fracking. Among the guests were author Harper Dimmerman, Elaine Sargent, Sharon Bush and Prudential Douglas Elliman’s Lisa Simonsen.
