why we talk silence most of the times

sitting together, the best we share is just the silence and some cliches.
why when we used to speak a lot, create fun , masti, then why we talk silence we are together.
I talked to many girls, with all flirts, and sincere appreciation and well-known lies and i was cherished , and was loved more and more.
but when it comes to serious business, we are just silence. because i think, relationship takes a sharp change from flirting to serious business. and the transition is a silence. I don't to lie or flirt anymore with you, but can flirt with others but not with you. we can talk either past , present future , lies or truth or some wonderworld affairs.
i can not talk past coz,  such a lovely lady must be having lot many stories which i won't deny to listen but yes i 'll feel jealous. present we can not talk much coz we are late a little bit, and moreover hardly anytime left  she is flying. future is uncertain and moreover we are like puppets drawn by the strings of our ego and destiny. I can n't lies and don't have any reason to say the truth coz you have not given me a reason yet.and spirituality does mean only when i am self contained and satiated. and i must say i am still half incomplete.

so it is better let us talk silence. silence is the most powerful language, it can express anything, just what you need is the apt to use this weapon.