My first thought was to make coconut brownies, pass them off as regular brownies, get him to take a big bite. Though I didn't make it to the grocery store over the weekend. So, I bought some coconut water, and had plans to pour that in his water glass when he wasn't looking. I was concerned, because pouring some in my own glass, I was reminded, it's not too clear.
I prepped to try it anyway, but the guy didn't have a water glass at his desk all day. I tried to plant thirst in his mind, making my own frequent trips to the water cooler, proclaiming each time that I was damn thirsty for some reason, maybe something in the air. But he paid no mind.
Eventually he got a Vitamin Water and drank it real slow.