EF DB Context not persisting Child record

Sample.cs

public class Parent
{
    public Parent()
    {
        Children = new HashSet<Child>();
    }
    public int ParentId { get; set; }
    public string Name { get; set; }
    public ICollection<Child> Children { get; set; }
}
public class Child
{
    public int ChildId { get; set; }
    public string Name { get; set; }
}
public class SampleContext : System.Data.Entity.DbContext
{
    public System.Data.Entity.DbSet<Parent> Parents { get; set; }
}
public class SampleRunner
{
    //Entry point of app 
    public static void Run()
    {
        var parent = new Parent { Name = "barry" };
        parent.Children.Add(new Child { Name = "william" });
        using (var context = new SampleContext())
        {
            context.Parents.Add(parent);
            context.SaveChanges();
        }

        using (var context = new SampleContext())
        {
            foreach (var p in context.Parents) 
            {
                Console.WriteLine("Parent name: {0}, id :{1}", p.Name, p.ParentId);
                Console.WriteLine("Children:");
                foreach (var c in p.Children)
                {
                    Console.WriteLine("\t{0}", c.Name);
                }
            }
        }
    }
}

RESULT : The data was being saved however i was not appropriately retrieving the data - either needs to be lazy loaded by marking the Children prop as virtual or eager load on retrieval (.Include())