My Comments first: Below my comments is an opinion piece by a priest about the "internal forum." Please note in particular what I have highlighted in red.
My understanding of the use of the internal forum is that the external forum must be exhausted first. It is not up to the person in this irregular situation to decide to forgo the annulment procedure altogether.
The next thing I was taught in the seminary and by a now retired bishop is that the priest cannot initiate the internal forum with a parishioner. The parishioner must initiate it during a spiritual counseling session or in confession.
If a decision of the penitent as described in the red I have highlighted below (or similar circumstance) believes that their second marriage is not immoral but rather, they are readmitted to Holy Communion with a codicil: there cannot be given public scandal by doing so. They should attend Mass where they and their circumstances are not known.
But the onus is on the person who decides to receive Holy Communion in an invalid marriage that technically is considered "living in sin." They acknowledge that receiving Holy Communion in such a "marriage" can bring them condemnation and eternal punishment. But they have chosen to follow their conscience for good or ill.
This seems to me to be less controling by the clergy of those in irregular situations that are considered sinful.
This is what John Allen reports concerning a more pastoral approach for couples in outwardly sinful second unions:
On Friday, another German cardinal, Reinhard Marx of Munich, tried to
articulate a consensus with the phrase “Not for no one, and not for
everyone.” His point was that not every divorced and remarried Catholic
is the same – there’s a difference, for instance, between someone who
walked out on their first marriage, and someone who was abandoned.
Marx was suggesting a case-by-case approach that would result in
some, but not all, divorced and remarried Catholics being welcomed back
Italian Cardinal Francesco Coccopalmerio, a top church lawyer,
offered the example of a woman who married a man outside the Church
whose first wife walked out on him, leaving him to care for three
(From another blog):
WHAT IS THE INTERNAL FORUM?
The internal forum is the forum of conscience. The external forum is the ecclesiastical
court of law.
Occasionally petitioners are afraid of dredging up the history of their failed
marriage. Some fear that their former spouse might do them harm. Whatever the
reason they cannot bring themselves to proceed with a formal case.
Then there are those cases where because of some error in judgment made by a
priest or a tribunal official justice was not rendered. Justice delayed is justice
denied. Or there simply aren't any witnesses who can provide cogent testimony for no one other than the married couple now divorced knows the truth.
If a person believes his or her prior marriage is invalid, but cannot prove
it they should seek counsel. Many Catholics have divorced and later remarried
before a Justice of the Peace without having consulted anyone, and without having
obtained a Church annulment.
This is a violation of Canon law, and they are presumed to be living in sin.
Suppose however that the legal presumption of the validity of the first was
incorrect. Suppose there was a defective intention which could not be proved.
Rare though it may be, such a thing can happen. Following one's conscience may
be justified in some circumstances. Every marriage is different. It is impossible
to judge the state of another person's soul based on the known facts of a case.
Sometimes things are not as they appear. Sometimes the so-called sinners are
saints and the upstanding saints turn out to be sinners.
Someone who wakes up from the nightmare of a disastrous marriage in a state
of disorientation may not understand the laws of the Church. The victim of abuse
and violence seldom has the objectivity of a trained professional. It takes
a long time to recover from a nightmare.
If such a person begins to heal, and for the first time finds true love, it
is not difficult to see how the new relationship can be perceived to be a gift
from God. The couple begins living together, feeling absolutely clean before
God. They try for an annulment but are told they have no case or they cannot
prove their allegations. What are they to do?
They may decide to consult a priest confessor or counselor for advice. The priest
may encourage them to follow their conscience if the facts seem to support their
moral convictions. The priest may not marry them because this would be simulating
the sacrament, but he can encourage them to trust a well-formed and certain
Pope John Paul II in his Apostolic Exhortation, Familiaris Consortio, has forbidden
couples from receiving the Eucharist if they are not validly married. Many of
them receive anyway believing that their second marriage is not a sin but a
Such a reception of Holy Communion violates the letter of the law, but freedom
of conscience comes into play here. The natural law right to marry must be weighed
against the doubt about the validity of the first marriage. Very few priests
would turn anyone away from receiving the Eucharist. The burden is on the person
receiving to do what they think is the right thing.