Natsu: Rude
I felt like Natsu would be very persistent no matter what. He would make sure he gets to be your boyfriend for all eternity.
Gray: it's not like I like you!
Since Gray is a tsundere, I felt like this song fit him. He would love to go on dates with you, but doesn't want you to say no to him.
Zeref: See You Again
It's hard to see Zeref. He's all over the place. From the woods of Tenrou to Alvarez as Emperor Spriggan. All you want to do is hug him!
Jellal: Criminal
Jellal may have been the bad guy, but he's yours. That was 7 years ago! He's changed and you love him for that.
Laxus: Let it Burn
Laxus is a tough guy, but after his break up with Mira...he came to you. This song was something he kept listening when you guys were together. The truth was that he never got over Mira..
Rogue: Everytime We Touch
Rogue is too much of a smol bean to admit this song to you. He feels all these emotions that his emo heart can't explain. He just loves you so much!
Sting: Feel Invincible
When Sting is with you, he feels invincible! You're his strength and he loves you for that. Everything he does, battles...guild meetings...tournaments... he uses your love for you as his determination.
Loke: Attention
You and Loke are on and off. He's always hanging out with all those girls in the Celestial Spirit Realm. Whenever you try to talk to another guy, he appears and takes you back.
Romeo: Cool Kids
Romeo is like a little yandere, he just wants his (Y/N)-senpai to notice him! Maybe being apart of the 'cool wizards' would make him noticeable to you?
Bonus:
Acnologia: Wait For You
Acnologia knows that he can't get you now. He's being hunted and that would cause you to be in danger. For now, he'll wait as long as he needs to.