Squirt, squirt -- drop. For a second he thinks the voice is just a sound in the song, but then, y'know, it registers. It's Billy, and it's definitely coming from that thing over there. So Dexter, realising that all this has been recording, drops the squirty bottle in the tank and turns around suddenly to face the tablet.

"Ghh -- crap!" There is a moment's flail, then, "Did you - see? All that?" Oh man.