此时不爱何时爱
[cĭ shí bù ài hé shí ài]
'If not now, then when' is an idiom from Jewish tradition used to encourage prompt action; if there's an ideal time for showing love, it would be in the present moment - now! In modern context, people usually use this line to express they don't want to miss the right moment to love someone or something with passion and sincerity.