How to get fillable values on created event

Hi, I'm making a model Contact related with other models with a Morph relationship. In order to make recyclable code I made a Trait with the relationship and some actions to do by the model where I implement this trait.

As you can see, when the model implents that trait is creating I try to create the contacts related with it getting them from 'contactes' filled parameter. The problem appears when I assign that contacts (contactes in catalan language) to the related model: Illuminate\Database\QueryException is throwed because when the model is creating eloquent doesn't know their id (obviously).

My question is: How can I retrieve the filled parameters from created method in order to assign the contacts to it? On creating method I must delete contactes parameter because if not, eloquent search for that column on model table and it doesn't exists. How can I temporaly store that parameter to retrieve it after create? Or, another way, how can I prevent to write it into the database on creating event?

trait Contacteable
{
    public function initializeContacteable()
    {
        if (! $this->with || empty($this->with)) {
            $this->with = ['contactes'];
        } else {
            $this->with[] = 'contactes';
        }
        if (! $this->fillable || empty($this->fillable)) {
            $this->fillable = ['contactes'];
        } else {
            $this->fillable[] = 'contactes';
        }
    }

    public function contactes()
    {
        return $this->morphMany(Contacte::class, 'contacteable');
    }

    public static function bootContacteable()
    {
        static::creating(function ($model) {
            if (array_key_exists('contactes', $model->toArray())) {
                $model->createContactes();
            }
            unset($model['contactes']);
        });

        static::updating(function ($model) {
            if (array_key_exists('contactes', $model->toArray())) {
                $model->updateContactes();
            }
        });

        static::deleted(function ($model) {
            if (! uses_trait(SoftDeletes::class, $model)) {
                foreach ($model->contactes as $contacte) {
                    $contacte->delete();
                };
            }
        });
    }

    private function createContactes()
    {
        Validator::validate($this->toArray(), ['contactes' => [new Contactes]]);

        foreach ($this['contactes'] as $contacte) {
            $this->contactes()->create($contacte); // Error here
        }
        unset($this['contactes']);
    }

    private function updateContactes()
    {
    // TODO
    }
}

Thanks