You can open your heart or close it. When you close it, the pressure builds up. And suddenly like a pressure cooker, the built up pressure can create a massive explosion.
There is a better way, keep your heart open. Allow the flow of feelings to keep coming out. Be natural. Express yourself freely. When you do this, you are comfortable with yourself as you express whenever you feel like. You are not playing a game of the mind, you are not trying to be over discrete. You are allowing your heart to express. The pressure never builds up. You feel relaxed.
Speak your heart.