Perhaps you should ask the priest who gave the lecture to discuss it with you. Without details, we have only speculation.
I will speculate that perhaps what the priest was discussing was this CDF document, in light of the current synod.
ewtn.com/library/CURIA/CDFDIVOR.HTM
Perhaps he was referring to those who live in continence due to obligations towards children, which is in this paragraph of the document:
The faithful who persist in such a situation may receive holy communion only after obtaining sacramental absolution, which may be given only to those who, repenting of having broken the sign of the covenant and of fidelity to Christ, are sincerely ready to undertake a way of life that is no longer in contradiction to the indissolubility of marriage. This means, in practice, that when for serious reasons, for example, for the children’s upbringing, a man and a woman cannot satisfy the obligation to separate, they "take on themselves the duty to live in complete continence, that is, by abstinence from the acts proper to married couples." In such a case they may receive holy communion as long as they respect the obligation to avoid giving scandal.