Truth? When to unveil and when to hold back?

I understand that communication is one of the key points of any relationship. i also understand that being open and honest is one of the many fundamental necessities in building any relationship be it vanilla or bdsm. I mean, if you cannot be open, honest and trust the one you are with then what is the point.

But is there a point when being too open, too honest, too trusting is more damaging then it is helpful?

I am often told that if truths are to cause anger and upset that the person I am with is obviously not for me and I understand this too. But still, I do have to wonder if there is a point in which lines should be drawn when some of the truths that you share can be in fact damage the faith or realness to a newly budding relationship.

I mean... of coarse 'eventually' these truths will have to come out but when is the appropriate time exactly? Do you wait until you know the person well enough to know how they will handle such truths and hope that the truth you hide will not overwhelm or blindside them? Do you just blurt it all out and hope for the best because at least they know from the get go what they are dealing with so there is no confusion later on as to why they threw their hands up in the air and walked away because in reality? the truth was in fact overwhelming and too much for them to handle.

And what do you do if one of these truths can be turned on you as a weapon but at the same time can become a very serious blindside if not warned what that truth is before it is smacking them in the face? Do you still hold tight to the truth to try to save yourself and hope for the best when it rears it's ugly little head in the future?

And what if the truth breeds so much complication that it has them slowly bringing their hands up and backing away because lets face it? Who likes 'that' much complications. Do you still share it and when? in the beginning so you know what you are both getting into or do you wait a while until you get to know them before you toss the complication card out and hope they don't run away screaming?

My next curiousity is, is if you hide so many truths then how are you to truly get to know someone? how can trust be established if you cannot be free to give everything you are even if that everything can sometimes be a nasty cold bite of reality?

The truths i speak of are not the simple ones like 'Oh by the way? I'm naturally blond and just dye my hair brown because i like how it makes my eyes pop' or the 'Oh by the way I spent 5 years in the pen for stealing a car' kind of truths. I'm talking truths that are the very make up of the person you are, the person you live with every day, the person you see when you look in the mirror and know that the truth behind that reflective glass is not as pretty as we can hope it to be. These truths will unlock the understanding of the person you are and without these truths? then the person you show is only part of what you see when you look in that mirror. and i am talking truths that cannot be hidden, truths that will raise up and make themselves known even without words, truths that you cannot hide because they are part of who you are.

These truths are what can break you, destroy you, or set you free... so when do you speak of these truths exactly?