Answer
Answer:
As-Salamu ‘Alaikom brother,
It is a cause for concern that women, like your sister-in-law, seem to be too receptive to their lower passions. Like Potiphar’s wife, she comes around to seize the attention of a man that is forbidden to her. By behaving in this way, she knows (at least subconsciously) that there is something not quite right about what she doing. However, with women like Potiphar’s wife, the danger includes you as well, as she can frame you in order to clear herself. This is how Prophet Yusuf was framed because of the service that found him daily in the presence of Potiphar’s wife. (Quran, 12:30)
Is there a reason why you have to be in your brother’s home so frequently? Yes, one can understand your indignation if, because of this woman, you are not able to visit your brother, but for all concerned, you should consider arranging to meet him away from his home. This would make a big difference and could contribute towards stabilizing their marriage.
Be in no doubt that she does not love you, but merely desires you. She has obviously chosen to marry well for personal security, but has not married for reasons that can cater to her needs. At least, this is what she believes.
As you have mentioned, “Their mutual relationship is not up to the mark”, and this problem is one that they will have to face together; to see how they can strengthen the nature of their relationship and increase mutual understanding. What is important for you now is that you distance yourself from this situation and continue your relationship with your brother through outside activities, like spending time together with other relatives and at the same time allowing your brother to spend time with his wife and put effort into his marriage.
Salams,
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