I know you don't like me. I know why you hate me. I know why you left.
What I don't know is why you've chosen to hurt Sora. He does love you far more than he ever loved me. You're wrong when you say that he cares more for me than you. I can see it in his eyes when he looks at you. I can hear it in his voice when he speaks about you. His soul is yours.
He felt obligated to stay with me. King Mickey and Queen Minnie almost pushed us into this. He tried to make me happy. He really did. But all the times he was with me, he thought of you.
Our first night together? I wanted it to be special. He wanted it to be special. He'll never admit it, but he called me by your name. It stung so much. It still hurts. Oh, he made sure I was physically satisfied, but my heart was broken. I had no emotional satisfaction. I could call him mine in body, but he was always yours in soul.
Our last night together? I'm really not sure he stayed hard for it. I faked that orgasm, just like I had every time after the first. He barely touched me that night. He was so distracted and sad from your letter.
I never told him this, but I've taken a lover. She's a very beautiful girl. Both you and Sora know her, but only you now know of her. I've kept her a secret from him, afraid that he'd hate me instead of just feel indifferent. She's wonderful in bed. I can't tell you how many times I've woken up from a particularly vivid dream with her name on my lips. I think Sora knows I've taken a lover, but I can't bear to tell him myself that it's Selphie.
I'm going to tell him that I'm leaving him. I want you to pick up his pieces. He always wanted you. Remember that. I'm going to mail this the second I get done writing it, then tell him I'm leaving him. I have to come clean now. I can't live this lie. I care for him and you too much, even if you don't care for me at all.
Please, let him make his choice like he wanted to long ago.
Come back to him, Riku. He misses you. I miss his smile. And I hope, someday, that you can forgive me for hurting both of you. I never meant to.