Whisk condensed milk and water in a bowl. Whisk in pudding and mix for 2 minutes. Let stand for 2 minutes or until soft set. Fold in the whipped topping
Arrange half of the cake in the bottom of a 14 cup trifle dish. sprinkle evenly with a layer of blueberries. Spread half of the cream mixture over the blueberries and gently spread. Top with a layer of strawberries. Layer the remaining cake and then more blueberries and top with the cream mixture. Finish by arranging the berries on top in a pretty pattern. Cover and refrigerate for at least and hour before serving.