How to get an object by exact occurrence in ManyToManyField?

Question

Django

There is a model:

class Dialog(models.Model):
    is_active = models.BooleanField(
        verbose_name='Активность', blank=False, default=True)
    members = models.ManyToManyField(
        "users.User", verbose_name='Участники',
        related_name='dialogues')

How can I get an object by exact occurrence of participants?
if you use members__in[...], it finds dialogs in which only one of the participants is in the list

I also tried using Q

dialog = Dialog.objects.filter( Q(members__in=[self.request.user,]) & Q(members__in=[another,]))

, also finds extra