non christian girl

please pray for my sister's son who is in affair with a non christian girl.May God stop this wrong decision

I love a nonchristian girl from Nepal her name is Kiran chemjong.But I couldn't open it out to her I love her so much that I cannot forget her .I know that that she too likes me from the way she behaves,but I found she has a boyfriend which she met on social media.Now I am very much desperate...