User blog comment:Crazylittlefreakgirl/Fairy Tail Official Pairings?/@comment-1535822-20130513114732/@comment-4829046-20130526145056

Lisanna X Natsu interactions were too small after Edolas.

Erza X Natsu interactions were more professional.

Mira X Natsu interactions were simply Mira crushing on Natsu's cute side.

Its a whole different story with Lucy. The guy does almost anything for her, on a deeper level. Its not romance, but its the thing that leads up to it in human relations.