Her Brother In-Law Seduces Her
19-2-2020 | IslamWeb
Question:
My husband is not hear from long time his younger brother is not nice he want to get close to me and says he love me i cannot tell it to my husband cause he is away and nobody will support me what to do plz help me
Answer:
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, sallallaahu 'alayhi wa sallam, is His slave and Messenger.
If this is the way your brother-in-law behaves with you, then he is really an evil man, trying to violate the honor of his own brother while he ought to be the one to protect it. It is incumbent on you to be firm with him and not give him any chance to manipulate your feelings and influence you. Any laxness with him might be a gateway for Satan and a means to Fitnah (temptation) and corruption. Allah, The Exalted, Says (what means): {O you who have believed, do not follow the footsteps of Satan. And whoever follows the footsteps of Satan - indeed, he enjoins immorality and wrongdoing. And if not for the favor of Allah upon you and His mercy, not one of you would have been pure, ever, but Allah purifies whom He wills, and Allah is Hearing and Knowing.} [Quran 24:21]
So beware of mixing with him, and avoid all situations that could allow him to be alone with you. You should also try to give him advice and remind him of Allah, The Exalted. If he stops, then all praise be to Allah; otherwise, threaten him that you will expose him and tell his brother, and perhaps he would be deterred. If he is not deterred, then you can tell a wise person of his relatives whom he respects and revers.
We advise you to supplicate Allah, The Exalted, to protect you from his evil. It has been authentically narrated on the authority of Abu Moosa Al-Ash‘ari 
that the Prophet 
used to say the following whenever he feared a people: “Allaahhumma Inna Naj‘aluka fi Nuhoorihim wa Na‘oothu bika min Shuroorihim (O Allah, we take You as a shield against them and we seek refuge with You from their evil).” [Abu Daawood]
It is worth highlighting that a husband should be keen on having his wife with him wherever he resides in order to spare her, as well as himself, the means to Fitnah. Rather, it is impermissible for him to be away from her for more than six months without her consent, unless he has an excuse for that.
For more benefit on being in seclusion with brother in-law, please refer to Fataawa 23186, 84531, 354103, and 242803.
Allah knows best.