小三不贱小四怎会出现
[xiăo sān bù jiàn xiăo sì zĕn huì chū xiàn]
It implies that if someone doesn't show inferior behaviors or characteristics (being humble or having bad qualities), certain troubles or annoying things (or people like small four in drama series) would not come out. In another way, this reflects that the person has been unfairly judged because she is a 'little three'.