Question 2: Here in Sri Lanka some Kaafirs (disbelievers) have accepted Islaam, especially Buddhists, but they stay married according to their former religions. One might be married to his niece and they have children. In such a case, we cannot separate them. What should we do?
Answer: If both spouses accept Islaam together, and they are married in a way that is impermissible in Islaam, they must be separated at once, such as a couple who accepts Islaam while the wife is her husband’s niece... read more here.