Stay Hydrated!
There is nothing more exciting than a cute girl flashing you a smile. It might be a good time to smile back, say hello, or ask for her name. That is, unless you are Zack filling a water bottle. The thought of sweet liquid gold filling your cup might be so distracting you can’t help but express the importance of hydrating.
It’s more likely that his response was a nervous one and he wasn’t actually that into his water bottle. As for the moan? I don’t have an explanation for that one. It’s a slip-up. It’s possible Zack’s dry phone has to do with his poor communication skills. What do you think?