They meet

Lucy is able to break free from the charming spell thanks to Natsu appearing (You can decide for yourself if あなた want to see this as a hint または not. But it's undeniable that the spell can only be broken によって someone whom you're もっと見る attracted to than the spell user)

Natsu grabs Lucy's arm and drags her along with him to Fairy Tail.

Lucy shows him her guild mark and first he acts as if he doesn't care, however over 300 chapters later it is shown that he did care about it.

Rescue Macao arc

Natsu considers Lucy to be his Nakama

Lucy saves Natsu and Macao

Day Break arc

Natsu is seen having broken...

■INFO : In the 最近 twitter Hiro Mashima, あなた can see a picture of Lucy Natsu キス in wedding dress デザイン byDesign Hiro Mashima.
Added によって FT Wiki
the 作者 himself (see picture). The 作者 also has a "NaLu" プロフィール on his account to tweet.
■OTHER INFO : The director of the movie of Fairy Tail in an interview 発言しました : Hiro Mashima wanted of the romance between Natsu and Lucy in the movie.
■"RECENT INFO" : Later of length look for for the fans, we have the confirmation of Natsu and Lucy and of their unions. We were also able to see in the former interview of the 作者 dating 2012...