What advice should I give my friend?

I am an Indian hindu girl, and one of my close friends is a muslim girl she is in love with a hindu canadian guy she meet trough some indian chat site. The guy is of mature age and is a doctor a Virgina Specialist.He keeps calling her on her mobile long distance calls and keep telling her how special she is and how much he loves her.She know they cant get married and the guy knows it too,but still they are pursuing this relationship why is it so? My friend keep telling me how wonderful he is and how much she loves him and he loves her.As a friend I am concern and wish to give her advice but I am not sure how to make her realise as I don't know myself if they have any future together. He seem to be serious as its strange that a doctor in a mature age living in Canada will make long distance call on her mobile every day and talk with her for hours ? Do you guys have any idea what this all is about, should I as a friend be supportive?