Friendship workflow using Entity Framework

ApplicationContext.cs

using System.Data.Entity;
using System.Data.Entity.ModelConfiguration.Conventions;

namespace Test.Models {
    public DbSet<Friendship> Friendships { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder) {
        /* USER */
        modelBuilder.Entity<User>().HasMany(u => u.Friends).WithMany();

        /* FRIENDSHIP */
        modelBuilder.Entity<Friendship>().HasKey(f => new { f.SenderId, f.FriendId });

        modelBuilder.Entity<Friendship>()
            .HasRequired(f => f.Sender)
            .WithMany()
            .HasForeignKey(f => f.SenderId);

        modelBuilder.Entity<Friendship>()
            .HasRequired(f => f.Friend)
            .WithMany()
            .HasForeignKey(f => f.FriendId)
            .WillCascadeOnDelete(false);
    }

}

Friendship.cs

using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace Test.Models {

    public class Friendship {

        public int SenderId { get; set; }

        public virtual User Sender { get; set; }

        public int FriendId { get; set; }

        public virtual User Friend { get; set; }

        public bool Accepted { get; set; }

    }
}

User.cs

using System;
using System.ComponentModel.DataAnnotations;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;

namespace Test.Models {

    public class User {
    
        public virtual ICollection<User> Friends { get; set; }
        
        public User() {
            this.Friends = new List<User>();
        }
    }
}