How to add condition to a manytomany relationship - django

Question

I'm a little new to Django, so my question may be basic, but bare with me. Let's say I'm sharing my posts with some of my friends (who are manytomany relation with the post), but also giving an extra condition for whether they can comment on it, or not. This condition, together with the name of the user to be shared with are submitted through a forum. Now my problem is that I don't know how/where to save this condition. I will show you some of my code.
Models.py
class Task(models.Model):
name = models.CharField(max_length=50)
text = models.TextField()
deadline = models.DateTimeField()
created = models.DateField(auto_now_add=True)
updated = models.DateField(auto_now=True)
user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='taskset')
shared = models.ManyToManyField(User, blank=True, related_name = 'shared_list')
def __str__(self):
return f"{self.name}-{self.user.username}"
class Comment(models.Model):
text = models.TextField()
task = models.ForeignKey(Task, on_delete=models.CASCADE, related_name='comments')
user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='comments')
created = models.DateField(auto_now_add=True)
def __str__(self):
return f"{self.user.username}-{self.task}"
Share form html
{% extends 'base.html'%}
{% load crispy_forms_tags %}
{% block content %}
<h3>Enter the Username of the Friend you want to share with</h3>
<form method="POST">
{% csrf_token %}
{{form|crispy}}
<input type="submit", value="Share">
</form>
{% endblock content %}
And the view processing it
def share(request, id):
task = Task.objects.get(id = id)
if request.method == 'POST':
share_with = User.objects.get(username = request.POST['username'])
if share_with is not None:
task.shared.add(share_with)
task.save()
return redirect('index')
else:
form = ShareForm()
return render(request, 'share.html', {'form':form})
Thanks a lot, I've been stuck for two hours, PLEASE HELP!