我胸小随我爸的不行

In Chinese culture, this translates loosely to 'my petite figure, just like dad's, doesn't cut it.' It uses physical attributes inherited from one’s father to comment lightheartedly on societal beauty standards or body image dissatisfaction, but it contains cultural sensitivity about the comparison to males. So, it should be understood more generally, perhaps as an expression of self-disparagement related to appearance or perceived social pressures on looks.