水是最解渴的液体你是最致命的唯一
[shuĭ shì zuì jiĕ kĕ de yè tĭ nĭ shì zuì zhì mìng de wéi yī]
Water is the most thirst-quenching liquid, just like 'you are the most essential and irreplaceable person'. Water serves as a metaphor here, where water, being life-essential, parallels the other person - suggesting how significant they are for their life or love life; without this particular person there’s insurmountable loss of vitality and pleasure.