For once, forget what others have done or what they could have done. The fact of life is, the only person we can hold responsible for our life is ourself! The only person, one can have control over is one's own self and not others. We can never compel others to act the way we want them to but we can certainly take charge of our lives to realise our wishes or our dreams!
You said, things were going right for you, and then suddenly your sister wrote a letter to your EX, and things simply went out of hand. No, to be very honest, things are never that simple. You need to realise and accept one thing very clearly that whatever happened, happened after the families got involved! Especially when both the families were trying to accept and acknowledge their children's decision. It was not like it happens in arranged marriages, where the families have known each other or manage to know each other through family, friends or acquaintances. In your case, your families were going by you and your gf's wisdom and judgement and happiness. Things were in a very delicate phase when your sister wrote a certain letter. You see, first of all, your sister, had no authority to act the way she did with your gf, especially with the families involved. The girl's family had no reason to take such insults from just about anybody. Also, I don't need to tell you the entire experience was scary enough for just about any respectable family to pause and perhaps step out of making a lifetime arrangement, when they know their daughter will be bullied and subjected to nasty treatment.
The worst was your absence! You just never came down. In that case, how do you expect someone or a family to go SIMPLY by your words, when you simply never acted, when you had no control over your own family?!?! (Your ex was absolutely right in seeking the families acknowledgement for your union) You see, our actions speaks louder than our words.
Please realise your ex was at least trying to keep things sane at her end, but where were you to reign in some nasty elements at your end? Your physical presence was required at least for the girlís family to understand that yes youíre a man who can take good care of their daughter. That you loved her enough to make things respectable for her and you were a man matured enough to handle difficult situations in a composed manner.
In fact, I feel, your ex did everything that was desired out of her, whereas I feel, you have let her down. If she was important enough, like you have admitted, you SHOULD have flown down to India to be with her, when it was absolutely necessary for the two of you together to bring your relationship at a respectable point. And above all, to CONVINCE her family, that their daughter meant the world to you and she was important to you.
Honestly, please accept the fact, that you have messed up big time. I hope you realise it now, that neither your sister, nor your family is at the receiving end, but itís you whoís here and whoís battling his emotions over something thatís long gone and dead, perhaps.
I keep on harping, a lie, after all is a lie. Please speak your mind, please be yourself and do what YOU think is right. Donít let people influence your life to the extent, that at the end of it all, you realise, you only wasted something precious for no reason at all. Only because you fell for convenience, or only because you were so influenced by others that you failed to differentiate right from wrong.
At this point in time, I can only advice you to communicate with your wife and you ex in complete total honesty. You need to take this off your chest. Apologise to people, especially these two women, if you feel, you have not been just to them. If you ex says, she doesnít want to hear from you ever again, please accept it and close the chapter forever. If your wife says, she wants her way out of this marriage, let her do that.
To be very honest, I donít think, people can ever fall out of love (I am talking about genuine affection!) but yes, people can certainly lose respect. And that exactly is the case here. If not love, please try and restore the respect! The people involved here couldnít live in peace, but they at least deserve to die in peace. So please be honest and communicate in total honesty. Itís important for the concerned people to know, that they loved and they lost, but they love!