"Is that not normal?" Annie wondered, a little embarrassed to ask but also much more interested, leaning against Diego's shoulder to peer at the buzzing vibrator. "I figured the different speeds were like -- you know, for variety."

Good hunch, Annie! Again, of all things -- she probably could have figured this out on her own, had she needed to (or if they'd been separated longer, and she'd elected to call Diego instead of bringing the live show to him.)