Short Answer: Keep advising your brother not to date girls or to be alone with them, either at home or anywhere else. If he persists, then you should eventually report his doings to your parents. The obligation in Islam to cover up other Muslims’ sins and not do or say anything about what they saw another Muslim doing is lifted for those who are in positions of power or authority. However, they should employ discretion, wisdom and caution in how they go about doing this, so that the situation is rectified, not made worse.
Assalamu alaykum, and thank you for your question.
As far as I have understood, sister, your query has two aspects.
The first is the Islamic ruling about an unmarried boy and girl being alone in a room together, with the deliberate intent to talk, meet, and/or be intimate.
The second aspect is whether you, as the boy’s sister, have to tell your parents about him dating a girl and bringing her back to his home, late at night, to his room.
If you further stipulated to your brother that you will tell your parents about this unless he brings the girl home, then should you still tell them, once he has fulfilled this condition?
The Ruling on an Unmarried Man & Woman Being Alone
Islam prohibits an unmarried male and a female, who are both past puberty, to be alone in such a closed space together, where no one else can see them, i.e. where there is complete privacy.
Prophet Muhammad (peace be upon him) said,
“No man is alone with a woman but the Shaytaan (Satan) will be the third one present.” [Al-Tirmidhi]
This restriction in Islam is there to prevent the crime of adultery from taking place.
Therefore, it is prohibited (haram) for a Muslim boy to deliberately meet with a girl in a private room, even if another person knows about their presence.
The Obligation to Prevent Evil vs Concealing Others’ Sins
In Islam, a person is disallowed from accusing another person of adultery, even if they have seen them commit the action with their own eyes, unless they can bring forward four male, adult witnesses who also saw the act taking place.
As is obvious, this makes it almost impossible for a Muslim to be punished and convicted for committing adultery, unless they confess willingly to the crime, or they did it in front of several other male adults.
This makes it clear that Islam seeks to cover up the sin of adultery, and it also prohibits a person who has seen two people meet somewhere in private, from telling anyone else about what they saw.
This is because this gives rise to rumors and gossip that can permanently tarnish a Muslim’s reputation, and plague them even long after they have repented for their sin.
Islam encourages guilty Muslims to hasten to repent for their sins, even if they have committed the major sin of adultery. Hence, the existence of the strict prohibition upon any Muslim, of accusing another of committing adultery, without there being four adult male witnesses to the act.
The question then arises: should a Muslim who sees or knows of another going towards adultery, do nothing?
Should they not try to prevent them?
For Those in Positions of Responsibility
The obligation in Islam to cover up other Muslims’ sins and not do or say anything about what they saw another Muslim doing, is lifted for those who are in positions of power or authority.
That is, those who possess the means and power to prevent the guilty person from committing that sin again, should use their power to prevent them from doing so.
However, they should employ discretion, wisdom, and caution in how they go about doing this, so that the situation is rectified, not made worse.
Therefore, any Muslim who witnesses another committing a major sin, is obligated to prevent the sin from happening again, especially if this sin involves the rights of others.
For example, if they see a thief steal something, they are obligated to report this theft to those whose rights were usurped viz. the owner of the stolen wealth, as well as to those who can prevent it from happening again, such as the security guards or police.
Our Responsibilities Towards Family Members
Sister, now you should do the following:
(i) Keep advising your brother not to date girls or to be alone with them, either at home or anywhere else.
Remind him that this is prohibited in Islam, and is a violation of the honor, chastity, and reputation of the girl he is going out with.
(ii) If he persists, then you should eventually report his doings to your parents. This will be an obligation upon you, since (as it seems) both you siblings are still living with your parents, they are accountable to and answerable for your actions in front of Allah.
Even if it causes a temporary rift in your brother’s relationship with you, at least you would have done the right thing, in accordance with Allah’s pleasure.
Doing the right thing is always hard. Even if it makes someone angry at you for some time, eventually, they will come around, once they realize that you only had their best interests at heart!
And Allah knows best. I hope that this answers your question.
Salam. Please stay in touch.