A/N - So the song "Two Out of Three Ain't Bad" came on the radio, and a wild plot bunny appeared...
"I wish you wouldn't take it this badly."
"How do you expect me to take it?" he shoved his hand through his hair. "I just asked you to marry me, and not only did you say no, you told me that you'll never marry me. I love you and I really saw us spending the rest of our lives together, and you just told me that it will never happen."
"You aren't in love with me." She looked at him sadly. "You are in love with the idea of being in love."
"Don't tell me what I feel." He huffed.
"I know it's not a consolation, but I really am sorry." She stood and walked over to the peg where her coat hung.
He sighed. "Look, it's still storming outside. The sleet is starting to change to snow. Just stay here tonight and we'll talk about this again in the morning."
"My answer won't be any different in the morning." She tilted her head.
"Then we'll talk about it tonight." He argued.
"We can talk all night, but it will get us nowhere." She paused, coat in her hand.
"How can you say that? Why is it you won't marry me? We're perfect together. Everyone says so. These past six months have been the best of my life." He seemed close to tears.
"I've enjoyed being with you. But we're not each other's happily ever after." She shook her head regretfully.
"How do you know that?" He cried. "Is there someone else? Is that it?"
"It's nothing like that." She assured. "I haven't even looked at anyone else."
"Then how can you say it's never going to happen with us, Luna?" He pleaded. "Don't I make you happy?"
"Yes, you do. That's why this is so hard. Please don't cry. Because even if you cry all night, it won't change the way I feel." She clamped her lips together, trying to hold back her own tears.
"Then why do you think it's never going to work with us?" He asked softly. "I'll take care of you. I'll protect you. I'll never let you be alone again. I'll take you looking for crumple horned snorkacks or whatever you want to look for."
"Neville, I want you and I need you, but I'm just not in love with you." She stared at him, willing him to understand. "It would be unfair of me to keep you from finding the person you were meant to spend your life with, and I care too much about you to let that happen."
She pulled on her coat, fishing her hat and gloves out of the pocket.
"Please don't be sad." She continued. "I can't lie to you. I can't tell you I'm something that I'm not. And I can't give you something that I just don't have."
"You're the only one I'll ever love, Luna." He vowed. "I'll never care about anyone the way I feel about you. No one will ever take your place in my heart."
"Don't think that way." She shook her head again. "You will find someone else. You won't feel the same way about her, and she won't take my place in your heart. She'll make her own place. And she will be what you need, because I'm not."
She opened the door and walked out into the snow.
Four years later, the night before he married Hannah, he sent Luna an owl. It simply said "Thank you."