public class Person
{
    public Guid Id { get; set; }

    public string Name { get; set; }

    public List<WorkItem> Tasks { get; set; }
}

public class WorkItem
{
    public Guid Id { get; set; }

    public string Description { get; set; }

    public Person Creator { get; set; }

}

CreateTable(
            "dbo.WorkItems",
            c => new
                {
                    Id = c.Guid(nullable: false),
                    Description = c.String(),
                    Creator_Id = c.Guid(),
                })
            .PrimaryKey(t => t.Id)
            .ForeignKey("dbo.People", t => t.Creator_Id)
            .Index(t => t.Creator_Id);

public class Person
{
    public Guid Id { get; set; }

    public string Name { get; set; }

    public ICollection<WorkItem> Tasks { get; set; }
}

public class WorkItem
{
    public Guid Id { get; set; }

    public string Description { get; set; }

    [ForeignKey("Person")]
    public Guid WorkItemCreatorId{ get; set; }

    public Person Creator { get; set; }

}