Is this misinterpreted idk but I think she likes gray and gray seems protective of her weather natsu treats Lucy like a close friend exactly like erza only he doesn't cry over her pain he cried for Erma and lisanna and was extremely hurt after lisanna died idt natsu is a guy looking for love... if anything it would be lisanna or lucy in a brawl over him
and of course let's not forget Hiro-san's recent drawing: [link]
[link] [link] [link] [link] [link] Note: in Hiro Mashima's previous work Haru and Ellie (The characters Natsu and Lucy are cosplaying in this one) ended up getting married
Omakes: "Beware of Guys Who Show a Keen Interest", "The Day of Fateful Encounter", "Rainbow Sakura", "Coca-Cola", "Happy in boots" and "Welcome to Natsu's House" Episodes: 50, 59, 83, 119, 122, 125, 127
If all of this does not convince you, it's cause you don't want them to end up together
Everyone has a different opinion. I don't really think that there is more between Gray and Lucy. I don't see where Gray is protective of her and Natsu treats her just like a friend. Everyone in FT is protective for their friends, obviously the main theme in FT is Nakama. And if you read the current arc you could see more hints about the development of Gray's and Juvia's relationship. I can't remember where in the Manga Natsu cried for Lisanna. But I could understand you if you just watch the anime. At the beginning they put many Nali flashbacks and such things but that all isn't canon material. That confused many people who just watch the anime. Fortunately, the anime producer changed it after some time. Also until now there was no reason for him to cry for Lucy. I acknowledge that Natsu and Lisanna were close friends in their childhood but after she came back there was almost no interactions between them. She seems to be more there for her siblings. Nalu seems to be the more logical pairing for me. Also the plot moves more toward Nalu, especially with the upcoming events. I think we will see more about Natsu's and Lucy's relationship in the future.