Get owner of context menu in code

this will give you the exact thing you want

private void OnDeleteClicked(object sender, System.Windows.RoutedEventArgs e)
{
    MenuItem mnu = sender as MenuItem;
    StackPanel sp = null;
    if(mnu!=null)
    {
        sp = ((ContextMenu)mnu.Parent).PlacementTarget as StackPanel;
    }
}

Hope this helps!!