If a husband is interested in polygamy and says that he may go for it if he gets more free time in future for two wives then is it permissible for the wife to make duaa that her husband changes his mind as she wants to remain as only wife of his in their married life and can't bear sharing him? he's still not sure due to his work hours being more but he may go for it if work hours reduce and the wife wants him to change his mind.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

It seems to us (Allah knows best) that it is permissible for a woman to supplicate that her husband does not marry a second wife, as there is no sin or aggression in it. A hadeeth reads, “The supplication of a slave continues to be granted as long as he does not supplicate for a sinful thing or for something that would cut off the ties of kinship.” [Muslim] Sheikh Abdul Kareem Al-Khudair was asked about this matter, and he answered that it is permissible.

Allah knows best.