Save Relation between User and Entity in ASP.NET MVC4

Save Relation between User and Entity in ASP.NET MVC4

I have an Exercise entity defined in my ASP.NET MVC4 Web Application. I'm
using the Form Authentication with the default AccountModels.cs class.
I have class which looks like
public class Exercise
{
private DateTime _DateCreated = DateTime.Now;
private UserProfile _Teacher;
public int Id{ get; set; }
public string Question { get; set; }
public int Anwser { get; set; }
public string Category { get; set; }
public int maxNbrOfAttempts { get; set; }
public string Hints { get; set; }
public virtual ICollection<Quiz> Quizzes { get; set; }
public DateTime Date
{
get { return _DateCreated; }
set { _DateCreated = value; }
}
public UserProfile Author
{
get { return _Teacher; }
set { _Teacher = value; }
}
}
Am I using the UserProfile correctly to link between an Exercise and a
logged in user? How can I get the current UserProfile in my controller?