Marrying paternal cousins after the father marries their mother
I have two married cousins; one of them has three daughters and a son and the other five sons. The father of the three daughters and the son died; his brother then married his widow and had from her two daughters and two sons. Is it permissible for the daughters from her first husband to marry his sons from his first wife?
If the situation is as you mentioned, it is permissible for any of the five sons (Part No. 18; Page No. 361) from the previous marriage to marry any of their three cousins, born of the mother’s marriage before marrying the father of these five sons, as long as there is no prohibitive impediment, such as breastfeeding or the like. The marriage of the five boys’ father to the three girls’ mother does not prohibit them from marrying. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.