Praise be to Allah.
The prayer of the prayer of the parents against the son will not be answered so long as the son is in the right and the parents are in the wrong. Allah will not answer their prayers (du‘aa’), because the type of disobedience that is forbidden is when the son does not do his duty towards them or he falls short in that. But if the father merely told his son to do something or not to do something, when the matter served no interest for the father, the son does not have to agree to that, such as if the father said to his son: Divorce your wife, with no reason. In that case the son is not obliged to respond to the demand of his father or mother, and his refusal to do that is not regarded as the type of disobedience that is forbidden, and if they pray against him, there is no sin or blame on him, in sha Allah.
Fataawa Samaahat ash-Shaykh ‘Abdullah ibn Humayyid (may Allah have mercy on him), p. 30