Love story of a 5-year-old son

One day, a Father saw his 5-year-old child writing something in a pad paper. He approached his kid and asked...

DAD: Son, what are you doing?

SON: I'm writing a love letter...

DAD: To whom?

SON: To my girlfriend, Dad.

DAD: (smiled) But you don't know how to write.

SON: Hmmm... That's okay! My girlfriend doesn't know how to read. It's LOVE Dad, YOU WONT UNDERSTAND!