He is wrong in talking to the sister I agree with that yes. Its not only the loss of a sexual partner that makes people commit suicide, drugs, alcohol, depression which could be as a result of multiple rejections in whatever way. The guy has just lost a marriage proposal, he is about to lose a very close friend so actually suicide isnt that hard to believe. Should this even be something that should happen of course not, ideally the sister and brother should never have had such a platonic relationship. If they hadn't this issue would never have arisen but hey-ho that's life no point in saying what if, all we can do is look for solutions. It's not an issue that someone just stops talking to me hence I commit suicide. If the person I talk to breakfast, lunch and dinner at uni stops talking to me fair enough I wont mind much. If my sister/mother stops talking to me that's a different matter. The latter are much much more closer to me. Similarly from the sisters description the brother and sister seem to very close to each other so if she stops speaking to him it is possible he may commit suicide. Most people would probably deal with it but not everyone is the same and we are trusting the sisters judgement here on his mental state. While the vast majority of people would move on, you do get the over-emotional/easily attached/those who have suffered many rejections etc etc who may contemplate suicide in such occasions. Forgive the adjectives, I don't mean to insult the brother but I am trying to show how some people may react and why they may react in such a way. So now we have established that suicide is an option to some, however bizarre it may sound to you or me, we need to provide solutions. And even then, if you dont think he will commit suicide give proper advice and tell the sister to stop contact with him as you do not think he will commit suicide. Personally, I don't think the fear of suicide is reasonable in many cases and often we exaggerate the effect we think our actions will have. Hence my own personal advice would be to the sister to stop contact. But while I don't think the brother will commit suicide, I don't use abusive language at the sister or make fun of her, rather I give my reasons for why I don't believe the brother will commit suicide and hence why I think she should stop contact. "The OP has got 2 choices in front of her: to maintain such a relationship or to cut it off. Clearly one is in accordance with the shari'ah and the other is not." No-one is disagreeing there. But there is a method to calling people to the shariah. She clearly knows which is in accordance, her issue is her fear the brother will commit suicide. Address that fear and address it in the proper manner. "And yes, the 'non-Muslim advice' may be pleasing to the ears, but it won't be so pleasing in the hereafter." Exactly, so stop being harsh with those people who seek Muslim advice. Stop calling them names, stop poking fun out of their questions, however basic they may be (not to mean the sisters was basic, talking general here). Its difficult enough to battle against your nafs and shaytaan when your full of desire, its even harder when you ask Muslims for advice and they poke fun at you for asking for advice. Be gentle when giving advice to anyone. I've talked quite a bit there, maybe a bit too much but too often I see this sort of thing happening when someone asks something and everyone pounces on them. Muslims need other Muslims around them, but if those Muslims will have that sort of attitude then they will go elsewhere and that will be the path to hell in the hereafter as you so implied. But we should keep in mind we were the ones who had the opportunity to guide them but turned them away with our harsh tongues, and that for us, to quote your own words: "wont be so pleasing in the hereafter"