He wrote a very significant statement on a piece of paper "I love you". Love is deep. It is deep in its meaning, deep in its commitment. He wrote that statement with a pen. You can erase pencil marks with an eraser, but this was written with a pen. A pen mark can't be erased.
When you write with a pen, you are writing with trust. And this trust is stored in the heart. The magical moments of the heart stay forever. Because the heart is always young, it enjoys the giving of love, and enjoys receiving it no less. The heart is a born romantic. Romance is adventurous. It needs daring to write a statement on someone's heart with a pen. Because writings with a pen are not a reckless game, but a deep feeling, emotion, care, affection, and commitment. The boldness to write with a pen comes with it responsibility. When you are ready to be responsible for the people you love, you can keep writing with a pen. You don't need to think, you don't need your mind to judge, because your heart is now free to write with a pen.
We often can't be sure of some people, some issues. So, we can't commit. Then, simply use a pencil. Make it clear to the other person you are using a pencil. Let there be no deceit of trust. A pencil is used by children when they are still learning and have to constantly erase their mistakes. If you feel you have grown up, you are willing to stand by your words, live by your trust, the time has come to write your emotions, and thoughts in willing hearts. This will then no more be a game which will end in a short time, instead it is the story of promised love delivered - the story of a trustful heart. Be careful of this. Because a pen mark can't be erased.