Leo DiCaprio and Bar Refaeli could be heading for a more permanent split after they went their separate ways after the Met ball on Monday. While Refaeli attended the gala and the after-party at Crown, DiCaprio partied at the Top of the Standard with his boys, dressed casually in jeans and a baseball cap. The actor avoided fotogs and kept a low profile while mingling with Naomi Watts and Carmelo Anthony, among others. Sources say Leo and Bar have been “going through a difficult patch,” but they are trying to work it out. A rep for DiCaprio declined to comment. Refaeli’s rep was not available for comment.