Yes, you can say "least". I wouldn't respond to the part about water, it's just noise to me. But if I want to complain or to express my dissatisfaction about whatever, then I would just directly say, "I am not happy about your ..." But a more effective way to communicate would be to directly assert my needs, whatever that is, like saying, "Okay, I have a situation here, can you help me with ...?" Something like that.