Override the init to pass the current user to the model form.

forms.py

class Formio(ModelForm):

    def __init__(self, user=None, *args, **kwrags):
        """
        Override the init to pass the current user
        to the model form.
        Then the current user will be passed to the form at
         initializing time in views or any other situation where
         ``request`` is available.
        """
        self._user = user
        super(Formio, self).__init__(*args, **kwrags)

Fuck it over!
Now with CBV it's easy to hack into forms ;)