It was an accident. A passing thing.
A mere second in which their hands brushed against each other. Even that small touch, however, was enough to cause his whole arm to tingle in the most peculiar way.
"S-sorry." Neville stammers and reddens.
"No trouble at all," says Luna and smiles rather radiantly.
He realizes he has never seen her blush, not even a little, until that moment. And it's lovely.