In a small bowl, combine bananas and lemon juice; let stand for five minutes. In another bowl, whisk the milk and pudding mix for two minutes. Refrigerate for five minutes. Stir in the sour cream. Drain bananas. Place half of the banana slices in eight parfait glasses, layer with pudding mixture, whipped topping, chocolate wafer crumbs and remaining banana slices. Refrigerate until serving. Enjoy!