title: EF Core Multiple Foreign Key mapping is causing an issue
body: <p>I am working with EF Core 5.0 in an ASP.NET Core Web API.</p>
  <p>I have an entity called Child</p>
  <pre><code>public class Child
  {
      public Guid Id { get; set; }
  
      public Guid FirstParentId  { get; set; }
      public Guid SecondParentId { get; set; }
  
      // Some other properties 
  }
  </code></pre>
  <p>The above child is a property in two parent tables called <code>FirstParent</code> and <code>SecondParent</code>:</p>
  <pre><code>public class FirstParent
  {
      public Guid Id { get; set; }
  
      public Child Child { get; set; }
      // Some other properties 
  }
  
  public class SecondParent
  {
      public Guid Id { get; set; }
  
      public Child Child { get; set; }
  
      // Some other properties 
  }
  </code></pre>
  <p>While configuring the foreign key relationship, I followed FluentAPI as follows in</p>
  <pre><code>protected override void OnModelCreating(ModelBuilder modelBuilder)
  {
      modelBuilder.Entity&lt;FirstParent&gt;().HasOne(a =&gt; a.Child).WithOne().HasForeignKey&lt;Child&gt;(b =&gt; b.FirstParentId);
      modelBuilder.Entity&lt;SecondParent&gt;().HasOne(a =&gt; a.Child).WithOne().HasForeignKey&lt;Child&gt;(b =&gt; b.SecondParentId);
  }
  </code></pre>
  <p>While creating the tables, it created as excepted. But while inserting some data into the <code>FirstParent</code>, I get an exception:</p>
  <blockquote>
  <p>The INSERT statement conflicted with the FOREIGN KEY constraint &quot;FK_Child_SecondParent_SecondParentId&quot;. The conflict occurred in database &quot;Tester&quot;, table &quot;dbo.SecondParent&quot;, column 'Id'.</p>
  </blockquote>
  <p>I cannot create all the child tables for every parent as I have lot of dependencies.</p>
  <p>Am I missing anything more to configure? Any solutions?</p>
  <p>Thanks in advance</p>