And I wouldn't know what to say in a love letter anyway. Would I mention how I long for your gaze, that feeling that you're looking only at me? Would I mention your voice, both smooth and lulling, when you're talking and you're singing? Would I mention your stories and your observations? Or that I love the feeling of your arm around me or when your hand is stroking my hair or when your lips are on mine? And each of those is but a minute part of you, almost insignificant compared to the rest. For me to eulogize a fraction of you would be an insult to the rest of you. So I wouldn't write a love letter.
Then perhaps I would write that I want to be with you, that I miss you and think of you whenever my mind wanders, which is often. But you know that, because I tell you on the phone, and when we chat, and when we text. And anyway, I have no way to describe how much I miss you, because I have never missed anyone like this before. I cannot tell you how much I want to be with you, because I have never wanted to be with anyone like this. To say that 'words cannot describe it' would only be another useless, flat cliché, like Pachelbel's Canon.
So then what is there left to say? Those things have all been said before. And I'm sure you have heard them all before.
Though I might be willing to sit down and hold a fountain pen to pretty paper, there is nothing to write. I just want to be with you, rather than thinking of you. But I'm sure you know that already. So I won't write you a love letter.