He didn't want to tell the truth when she asked why he started a fire in an empty classroom. Truly, he had previously wanted alone time to think... but he wanted somewhere warm and inviting at the same time. However, the horrible thought of her leaving made him not vocalize his true intentions. Instead, he said something along the lines of "Just wanted to see if I could," in response.
Then she sat down. His stomach swooped, he felt momentarily as if he were in free fall. His heart beat still faster and harder. She gave him consent to draw breath, and as he did so, inhaled the intoxicating scent of perfume and fresh rain... it was intoxicating. He sniffed again, trying to be casual. He smiled at her back every time she smiled at him, the only reaction he had to the now familiar boiling sensation in his stomach.
"Thanks for letting me breath by the way, for a moment I forgot how." he said a little awkwardly, without knowing what else to say. He accompanied the comment with a faint smile. He secretly wished she would smile back at him again.