Muslim girl involved with White Christian Boy without her parents knowledge!

Hello Muslim Brothers and Sisters,

I am Pakistani, and so is this 17 year old girl that I know. I know for a fact that she has been seeing a Christian White boy without her parents knowing, even acting sexually with him! I have expressed my disapproval to this girl, and she knows her parents would go CRAZY if they knew.

I do not want her to be involved with this boy anylonger, as I do not think it is good for her wellbeing. It is not because I myself want to be with her, I just think she is being disrespectful to her culture, family, and religion.

How can I get this relationship to stop? I have thought of phoning her parents and telling them anonymously, but she would figure it was me and be very angry with me, which I do not want. I still want her to be my friend. I have tried talking to her, but she will not listen. Im afraid the only alternative is for her parents to find out somehow, which I fear might be too late.

So, how can this problem be resolved?