Enjoy your site very much and has helped me more than you will ever know. What do you suggest if you have a couple up in years and have been married 4-5 times each, but they are summer visitors who are members of another congregreation but are here four months out year? Who responsibilty is it to confront them? Where they go, they accept problem remarriages. Should we disfellowship them even though they are members at another congregation?
Though they consider themselves members of another congregation, the reality is that they are members at your congregation for several months each year. It would not be proper to ignore someone in sin, even if they are only with you a few days and you are aware of a problem. "For we must all appear before the judgment seat of Christ, that each one may receive the things done in the body, according to what he has done, whether good or bad. Knowing, therefore, the terror of the Lord, we persuade men; but we are well known to God, and I also trust are well known in your consciences" (II Corinthians 5:10-11). Thus, the primary aim is to try to persuade sinners out of their sins.
If the couple does not wish to listen to what the scriptures say about their situation, what is most likely to happen is that they will leave and blame you. If in the rare case they decide to stay and refuse to leave their sin, then withdrawal is required.