It's too easy to dismiss something by declaring it's 'western culture'. We might be better advised to examine what 'bf and gf culture' means, whether the people involved have the emotional maturity to handle relationships and so on and so forth. Love has always existed in Indian culture as in all others, and so have casual relationships (whether sexual or not). These are nothing new. If they are more frequent now than before, it is as much a result of women emerging from behind the purdah as the much-reviled influx of western culture. Sometimes the people involved in a relationship don't understand what love is about. Sometimes people hurt the ones they love. And yes, sometimes people show their affection for each other in public.
It's all a part of the mad, mad world. Society changes itself to adapt to the people in it. After all, what's the point of being young and foolish if you don't have someone just as young and foolish to share your youth and folly with?
