乐此不疲 樂此不疲

    lècǐbùpí

    1. Idiomto enjoy something and never tire of it (idiom)

    他乐此不疲地收集邮票,已经坚持十年了。Tā lècǐbùpí de shōují yóupiào, yǐjīng jiānchí shí nián le.He has been collecting stamps for ten years, never tiring of it.