One remark to what has been discussed before: I always thought that a real love or friendship meant to be able to trust each other totally, without fear that if you don't keep it hidden, it could be easily split by some fool from outside, or that you loose each other due to some misunderstanding. Because if you do, it wasn't real and if it's not real, it's not worth it so what do you have to loose? If something goes wrong in a relationship there might have been some intrusions or whatever caused by a third party but it's up to you how you deal with it. You might kick each other to the butt because you believe someone said something which isn't true or misunderstand the motives of the other or get wrong what they wanted to say et. etc.... Well there is always some potential danger outside but it's finally up to you 2 how you deal with it. So you cannot really blame the outside world, on the contrary if you can face a lot of hardship succesfully, it can only make you stronger.
I am not against keeping hidden online relationships, as everybody is entitled to privacy, just wanted to express this thought.