What is the lawful solution for the second wife to become unmarriageable to the suitor? Is it permissible for the suitor to marry one of the second wife's daughters with the intention of divorcing her, so that the second wife becomes unmarriageable to him, and then marry the eldest daughter? Is it permissible for him to be nursed by the second wife so that she becomes unmarriageable to him?

The suitor's suckling from the mentioned woman is not permissible, because the suckling of an adult does not establish a prohibitive relationship according to the majority of jurists. And if we were to adopt the view that it does establish a prohibition, then the fiancée would become the suitor's sister through fosterage.

As for the second option, which is the suitor marrying the daughter of the mentioned woman with the intention of making the mother unlawful for him, this does not lack one of two situations:

1. That the marriage contract is merely superficial, which is forbidden by Islamic law. 2. That he marries her with the intention of divorcing her, and this is a matter of scholarly disagreement. Some scholars permit it, while others forbid it because it falls under the ruling of mut'ah marriage (temporary marriage). In any case, it involves deception and forbidden fraud.

Therefore, we advise avoiding these solutions and dealing cautiously with the fiancée's father's wife.