久处不厌乍见之欢
[jiŭ chŭ bù yàn zhà jiàn zhī huān]
This phrase conveys the paradoxical feelings of not being bored with someone after spending a long time with them, and also finding joy in newly meeting someone. It implies someone is consistently charming and lovable over time, while also creating a strong first impression. Both are desirable traits for forming good relationships.