How to keep a reference to a class property updated?

So lets say I have Class 1

public Class1
{
    Class2 myClass2;

    public Class1()
    {
        myClass2 = new Class2();
    }

    public SomeObject anObject
    {
        get;
        set;
    }
}

and Class2

public Class2
{
    private SomeObject _myObject;
    public SomeObject MyObject
    {
        get{ return _myObject;}
        set{ _myObject = value; }
    }

    public void DoStuffToObject()
    {
        _myObject.Property = newValue;
    }
}

How can I keep _myObject in Class2 the same as anObject in Class1 if I set anObject equal to a different开发者_StackOverflow object. So if I change anObject in Class1 _myObject is Class2 changes as well? Is this a good solution:

(in Class1)

    private SomeObject _anObject;
    public SomeObject anObject
    {
        get{ return _anObject; }
        set{ _anObject = value;
             if(myClass2 != null)
             myClass2.MyObject = value;
        }

    }

It seems a little extraneous, but sense you can't pass a property by reference I am a little stumped.

Thanks

---

public Class1
{
    private Class2 myClass2;

    public Class1()
    {
        myClass2 = new Class2();
    }

    public SomeObject anObject
    {
        get { return myClass2.MyObject; }
        set { myClass2.MyObject = value; }
    }
}