Customers at Da Silvano got an eyeful with their meals when couple Sean Lennon and Charlotte Kemp Muhl dined with four other pals Thursday. “People were enjoying glimpses of Charlotte’s cleavage,” said a spy (who was not Brent Musburger), adding, “It popped out of her cutout top a couple of times.” Then again, sexy Muhl’s posed without her top as a model in spreads for S Magazine and others. Also there at a separate table and fully clothed were Lou Reed and Laurie Anderson.