I get confused with Form.Close() - winforms

Question

So I link delegate from Form2 to This_Hide() fuction in Form1, then i link delegate from Form3 to delegate in Form2(which link to function in Form1 as I said) but I get confused that it still work although Form2 is CLOSED when I making instance of Form3. If Form.Close() method closes Form2 and dispose it how delegate from Form3 can still call function(delegate) from Form2..?
namespace TestingMachine
{
public delegate void FxDelegate();
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
Form2 fr2 = new Form2();
fr2.Delegate_Father_Hide = new FxDelegate(This_Hide);
fr2.Show();
}
public void This_Hide()
{
this.Hide();
}
}
}
namespace TestingMachine
{
public partial class Form2 : Form
{
public FxDelegate Delegate_Father_Hide;
public Form2()
{
InitializeComponent();
}
private void Form2_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
Form3 fr3 = new Form3();
fr3.Delegate_Hide_Grandfather = new FxDelegate(Hide_Grandfather);
fr3.Show();
this.Close();
}
public void Hide_Grandfather()
{
Delegate_Father_Hide();
}
}
}
namespace TestingMachine
{
public partial class Form3 : Form
{
public FxDelegate Delegate_Hide_Grandfather;
public Form3()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Delegate_Hide_Grandfather();
}
}
}