Natsu didn't really know this happened. All he remembers was meeting her and the realization for his feelings, everything in between was a joyful blur. Ok so that was lie, he remembers everything that happened between then and now. How could he not? After all those years were the best years of his life - so far! Ok so maybe he was giving her a little too much credit but he didn't care. After all he loves her.
"Uh Natsu?" Lucys worried tone snapped him back into reality.
He couldn't help but smile to himself, "Lucy Heartfilia, I love you."