Scorpius gives James a look. Really. Really. He's really asking that question?

"Already told you: momentarily insanity," he says, half swallowing his words. Merlin, this is embarrassing, but... Scorpius stops moving, letting the water still between them. James isn't swimming away. And he's not diving for Scorpius's throat. In fact, he doesn't even really sound all that upset. Just shocked, maybe.

"And because you looked like you wanted me to."

Yep. Just going to dig his watery grave deeper.