Entity Framework Code First Mapping Foreign Key Using Fluent API

Question

I have the situation where a User can have several addresses. Accordingly, I have an ICollection on my user class. But I also want the user to be able to choose a default address. So I've done the following:

public class User 
{
    public int Id { get; set; }
    public int? DefaultAddressId { get; set; }
    [ForeignKey("DefaultAddressId")]
    public virtual Address DefaultAddress { get; set; }
    public virtual ICollection<Address> Addresses { get; set; }
    //properties were removed for purpose of this post
}

I would like to remove the public virtual Address DefaultAddress { get; set; } altogether, keep the DefaultAddressId and map it using the Fluent API instead because the current setup is causing a lot of trouble (in this and other classes where I have a similar setup). So can this be done using the fluent api?

UPDATE: The address class currently doesn't have any reference to the User class, it's a uni-directional relationship. But yes, an address belongs to only ONE user, it's not a many to many relationship. Here's the address class:

public class Address
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Details { get; set; }
    public virtual Area Area { get; set; }
}

Answer 1

I would personally move the Foreign Key relation from User to Address, and add an IsDefaultAddress property on the address class.

public class Address
{
    public int Id { get; set; }

    // This property marks the FK relation
    public virtual User User { get; set; }

    public string Name { get; set; }
    public string Details { get; set; }
    public virtual Area Area { get; set; }

    // This property signals whether this is the user's default address
    public bool IsDefaultAddress { get; set; }
}

EF will know that it needs a Foreign Key relation between Address and User.

This would simplify your model a great deal. That is, of course, if an address can only belong to one user (as asked by Slauma in the comments).