Adam stood rigid, jaw taut, balled fists by his sides, his eyes unreadable as they stared at his brother. His expression was a storm barely contained, almost thunderous—he was trying, and failing, to look calm, unbothered, civil.

I thought it was funny, then strange. Why would he look like that? It's not like Noah and I were copulating on the dance floor; we were just dancing.

My eyes found the woman he had been dancing with; she was frowning in confusion, and for a second I thought, playfully, that she might have had a crush on him.

Meanwhile, the crowd was beginning to notice the standoff, their feet shifting uneasily,...