Shalom and thank you for your question!
Sometimes severe problems develop when a person feels they have met a suitable life partner for marriage, and the potential partner shares this feeling, but the parents object strenuously. Sometimes the parents express their opposition in an extreme way, including threats of disowning the children.
The question then arises, should the son obey his pareיוts and give up on his fiancee, and should the daughter give up on her fiance?
The position of Halacha is that despite the pain of the parents and the possible effect on the future, a son or a daughter are not obligated to heed their parents opinion in this particular case. (רמ”א יו”ד רמ, כה)
The parents mean well, however each person has free choice regarding his future. It is true that sometimes the outcome in such situations is tragic, but the decision must nevertheless be made by the couple. The son or daughter are not the possession of the parents, they are independent people who have the right to decide about their future. Of course children should share and consult with their parents, and understand that usually they are well intentioned, and many times they are also right, nevertheless the decision remains that of the couple.
In many cases when parents are informed of this Halacha, the situation improves, and instead of threats, constructive discussion takes place. If despite this, the parents continue to strongly oppose and even threaten to break off contact, the son or daughter are still not obligated to listen, and as is mentioned (in Halacha 20 ibid) siblings of the couple do not have to listen to the parents if they ask them not to participate in the wedding, as one does not listen to a parent if the parent tells you to do something which is against Torah law.
It is important to emphasize however, that there were times that the Lubavitcher Rebbe gave blessings for a wedding on condition that the parents agreed to it, The explanation apparently is that if parents are opposed they presumably have a reason that is worthwhile taking into consideration. Having the parents’ blessing surely increases the G-dly blessings for the occassion.
The best option is to judge every case individually, and to take counsel with a Rabbi or a person well versed in such matters, sharing with him all the relevant details.
Much success!
