Symfony2: many-to-many with extra columns no Lazy in Twig - symfony

Question

I know, there are a lot of posts about this topic, but for me it is imposible to get the right solution.
I have 2 entities with the relationship many-to-many and in that relationship many colums (that means 3 entities). I have two questions:
The SQL is Lazy-loadinig, but I write "SELECT l, ul ...", so I want to select both tables. Why still Lazy-loading?? is There any config anywhere??
How can I show it in my Twig's Templates??
My entities are more or less like that:
Usuario:
/**
* Usuario
*
* #ORM\Table()
*/
class Usuario
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="nombre", type="string", length=255)
*/
private $nombre;
...
/**
* #ORM\OneToMany(targetEntity="UsuarioLibro", mappedBy="usuario")
*/
private $libros;
public function __construct()
{
$this->libros = new ArrayCollection();
}
...
/**
* Get libros
*
* #return \Doctrine\Common\Collections\Collection
*/
public function getLibros()
{
return $this->libros;
}
}
Libros:
/**
* Libro
*
* #ORM\Table()
*/
class Libro
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="titulo", type="string", length=255)
*/
private $titulo;
...
/**
* #ORM\OneToMany(targetEntity="UsuarioLibro", mappedBy="libro")
*/
private $usuarios;
...
public function __construct()
{
$this->usuarios = new ArrayCollection();
}
...
/**
* Get usuarios
*
* #return \Doctrine\Common\Collections\Collection
*/
public function getUsuarios()
{
return $this->usuarios;
}
}
UsuariosLibros (the relationship):
/**
* usuario_libro
*
* #ORM\Table(name="usuario_libro")
* #ORM\Entity
*/
class UsuarioLibro
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var integer
*
* #ORM\Column(name="tener", type="boolean", options={"default":0})
*/
private $tener;
/**
* #var integer
*
* #ORM\Column(name="leer", type="boolean", options={"default":0})
*/
private $leer;
/**
* #ORM\ManyToOne(targetEntity="usuario", inversedBy="libros")
*/
private $usuario;
/**
* #ORM\ManyToOne(targetEntity="libro", inversedBy="usuarios")
*/
private $libro;
public function __construct(Usuario $usuario, Libro $libro)
{
$this->usuario = $usuario;
$this->libro = $libro;
}
...
/**
* Get usuario
*
* #return \JavierGlez\Osprey\FrontendBundle\Entity\usuario
*/
public function getUsuario()
{
return $this->usuario;
}
/**
* Get libro
*
* #return \JavierGlez\Osprey\FrontendBundle\Entity\libro
*/
public function getLibro()
{
return $this->libro;
}
}
I can serch all the content with this SQL:
$query = $this->getEntityManager()
->createQuery(
"SELECT l, ul FROM JGOspreyFrontendBundle:Libro l
LEFT JOIN l.usuarios ul
LEFT JOIN ul.usuario u
JOIN l.colecciones c
WHERE c.id = :idColeccion AND (u.id = :idUsuario OR u.id IS NULL)")
->setParameters(array('idColeccion'=>$idColeccion, 'idUsuario'=>$idUsuario));
When I try to debug the variable, then the program gets blocked.
Anyone can help me???
Cheers