He'll try. Just tell him when to stop. That should be all the precaution he needs. Besides there was no Happy to fly in and tease them and make Natsu lose control of his flames. With Lucy's instructions it couldn't possibly come to that.

Except she just had to go and say that sentence. He suddenly goes still and for a moment Natsu seems to space out remembering what happened last night. His hand starts to move up to touch the cheek she kissed last night but he stops half way snapping out of it with his cheeks lightly tinged in pink.

"Of course. You'd do the same for me if I were in your shoes." Not even questioning that but more than anything he's clinging to that as a distraction.