Putting the idioms into action
A phrase to confess your love:
我对你一见钟情。Wǒ duì nǐ yī jiàn zhōngqíng.
I fell in love with you at first sight.
To flirt and make a date:
A: 今天我能约你吗？Jīntiān wǒ néng yuē nǐ ma?
Can I see you later today?
B: 我们前天才见过呢。Wǒmen qiántiān cái jiànguò ne.
Didn’t we just see each other the day before yesterday?
A: 对我来说是一日不见如隔三秋。Duì wǒ lái shuō shì yī rì bùjiàn rú gé sānqiū.
One day apart from you (to me) feels like three years.
Or even to propose:
我愿意和你相濡以沫，白头偕老。嫁给我吧！Wǒ yuànyì hé nǐ xiāng rú yǐ mò, báitóu xiélǎo. Jià gěi wǒ ba!
I want us to moisten each other with our spittle and stay together till our hair turns gray. Marry me!
And if things turn ugly:
你为什么对我若即若离？Nǐ wèishénme duì wǒ ruòjí-ruòlí?
Why are you apart from me even when we’re together?
是喜新厌旧了吗？Shì xǐxīn-yànjiù le ma?
Are you tired of this relationship and ready to move on?
我们最好还是分道扬镳吧！Wǒmen zuì hào huán shì fēndào yángbiāo ba!
It’ll be better for us both if we take separate paths now!
In other words, better to be happy and alone than miserable with someone else.
We wish you much happiness in all your relationships!