Theo has learned from the other boyz that water tastes better fresh from the tap rather than in a bowl. After a meal he'll meander to the main level bathroom, hop on the back of the toilet and meow.
This is a call for me to turn on the bathroom tap. Theo will then stand on the back of the toilet, balance his front legs on the edge of the sink and lap up water.
The upstairs bathroom has a vanity and this is Thompson's and Diego's preferred sink because it's much easier (and roomier) for them to drink water from a tap. For some reason Theo seems to think the leap on to the vanity is beyond his capabilities so he has never joined the other two in the joys of upstairs tap water refreshment. Last week he was standing in the upstairs bathroom meowing so I lifted him on to the vanity and turned on the water for him. Now every night since he has done the same thing whenever I go upstairs.
It only took a couple of years but he has finally trained me.