MVC : Does Code to save data in cache or session belongs in controller

I'm a bit confused if saving the information to session code below, belongs in the controller action as shown below or should it be part of my Model?

I would add that I have other controller methods that will read this session value later.

  public ActionResult AddFriend(FriendsContext viewModel)
  {
        if (!ModelState.IsValid)
        {                
            return View(viewModel);
        }

        // Start - Confused if the code block below belongs in Controller?

        Friend friend = new Friend();
        friend.FirstName = viewModel.FirstName;
        friend.LastName = viewModel.LastName;
        friend.Email = viewModel.UserEmail;            

        httpContext.Session["latest-friend"] = friend;

        // End Confusion

        return RedirectToAction("Home");
    }

I thought about adding a static utility class in my Model which does something like below, but it just seems stupid to add 2 lines of code in another file.

public static void SaveLatestFriend(Friend friend, HttpContextBase httpContext)
{
    httpContext.Session["latest-friend"] = friend;
}


public static Friend GetLatestFriend(HttpContextBase httpContext)
{
    return httpContext.Session["latest-friend"] as Friend;
}