Here is the story, it happens during the 1 year after the war, they went to the hot spring.
Gray is panicked because he has trouble seeing it as a couple with Jubia and that's not what he's doing because he's shy XD.
Erza, bored because jellal is not there or is waiting jellal, gray and natsu come to change his ideas.
Gajeel and levy talk quietly.
And natsu and lucy are eating, but lucy woods too much and skips XD.
No, but people do not get excited for that, everyone has their opinion on that.
Some do not like romance in manga, others do not like couples and there are also the opposite.
From the training camp and Christmas, mashima puts the couples well ahead and does not try to mix things.
Stuffed Lucy does not even look gray, she only has eyes for natsu.
Levy, erza and wendy, do not do anything to break his couples by participating, mashima did not try to make a natza or grayza.
Mashima put a romance in his manga, he must hold it, as already said if it bothered him that much, he will have stopped, the fans have not forced him to continue.
The gruvia could have ended after the dragon attack, when gray said "no" to jubia, he did not do it so it did not bother him to do this couple.
The relationship of natsu and lucy "" more than friends less than lovers "" is the relationship they have from the beginning, so it is normal that we see it evolved and concluded.
Lucy loves natsu and we can see what Natsu is doing, but since she's a jerk, she, like us, we do not know if Natsu understands the principle of "true love".
Already I assume that natsu do not know how to do children XD .
So from there, either it is lucy who will have explained everything to natsu and asked him if he wants to marry him, like biska did with arzak.
Either natsu will ask him but in a WTF XD way, not at all conventional XD, in a way to natsu.
As I read in a fanfic, it's typically like that I see, Natsu asked him XD.
A big anything XD.