Okay, 2 questions.
1. What are they pouring on her?
2. Is there a tag for "short_circuit"?

1) Soda, water, tea (granted it's not shown as hot)?
2) Good question though Aigis mentions in the game that she's waterproof so that's probably not an issue. An exposed Papillion Heart on the other hand...

Whatever they're pouring is irrelevant really, Aegis did imply in the game that touching her Papllion Heart turns her on.