It hits Natsu one day; it's out of the blue and it's also kind of disturbing, but he's Natsu, so he can deal with it.
Monsters are one thing, he decides. But girls are a completely different story.
Lisanna is back from the dead- well, Edolas. It had been one of his fantasies ever since he was like… seven (besides finding Igneel), and he should be elated.
And, well, he is… except he's not.
Lisanna is comfortable and cute and happy and she's always been in his thoughts, somewhere in the corner of his mind- except for the fact that she's not Lucy. And inexplicably, this bothers him.
Lisanna doesn't notice this; she talks brightly next to him, and he answers nonchalantly, because he's noticing the wrong things. She's his childhood friend, yes, and he always thought that she was the one who had taught him love and all that, except she's not Lucy! And his mind is screaming that he's wrong, always has been. He's noticing things like how Lisanna has a pretty smile, but it's not as pretty as Lucy's. He watches as her hips swing and she laughs like she's happy- but she doesn't laugh as if she is happiness, like Lucy does. And Lisanna is cute, but Lucy is pretty.
(Somewhere, in the back of his mind, Natsu acknowledges that there is something seriously wrong with him because he normally doesn't think about things like this. But the shock of seeing Lisanna and Lucy in the same room seems to be doing funny things to his head).
(He analyzes the situation with uncharacteristic seriousness, wondering what the hell has happened to him, and if he should approach the situation or just screw it, and go beat up Gray or something.)
Lucy is nowhere to be seen- wait, there she is.
Lucy is sitting next to Erza and Gray, laughing at something the older woman has said. Her entire body shakes with the laughter, and Natsu somehow feels off, sitting with Lisanna just three tables away. Lisanna has stopped talking, and looks up quizzically. Grudgingly, he meets her gaze.
"You okay, Natsu?" Lisanna says, with a touch of concern in her voice. Her concern doesn't make him feel as warm as it does when Lucy asks if he's okay, her eyes furrowing adorably. Lisanna's eyes are friendly, but Lucy's eyes are warm, and make him feel at home.
Abruptly, Natsu feels like the current situation is very wrong.
"Lisanna," Natsu begins huskily, and then doesn't know how to finish. Lisanna is looking at him sweetly, expectantly.
But she's not Lucy, is all he can think.
To his surprise, Lisanna gets up when she sees his eyes unconsciously trail to Lucy's figure, (which is now staring in disgust at a stripping Gray. Erza decides to proceed to hit him over the head) and she smiles a little sadly.
"Natsu," Lisanna says softly. "It's about time you got it."
Natsu's attention is momentarily diverted to Lisanna, and he blinks in confusion. Lisanna is chuckling, and when she opens her eyes to look at him, Natsu is momentarily afraid.
Because monsters are one thing, and romance is a totally different thing altogether.
"You know," Lisanna chides gently, "even I figured it out. From the moment I saw you two together."
Lisanna turns and approaches her siblings, picking up into their conversation like she'd been there all along. Natsu gets the feeling that with her siblings is where Lisanna is at home.
And as for him…
Natsu is confused, but not dense enough to not get why he is. After a split moment's consideration, he leaps up and to Lucy's table.
Erza greets him with a whack across the face, Gray greets him with a misplaced insult.
Lucy greets Natsu with a smile that blinds him with its honesty, and Natsu returns it, deciding for once to ignore the assaults from his other friends.
Settling into routine, Natsu slips into an argument; his body never strays from Lucy's, however.
Next to him, Lucy smiles knowingly.