... is all I ask of you
Sometimes when it is too late, you don't know what to do, and what to say, and everything is left unsaid. And you will start to regret that time when you could say it all, that moment when everything was perfect, yet you had that feeling inside you had to pour out. But you were scared to spoil the moment, and hence you kept it all inside. Thus it builds up and becomes something that eventually destroys the defense you built outside. And all the walls are falling down, and everything is not what it seems anymore. You don't even realize it, as the weakness comes from within yourself, a part you thought was strong enough to endure anything, come what may.
Say it only if you mean it.
If you don't, then you may forever hold your peace.