不爱是最冠冕堂皇的理由
[bù ài shì zuì guān miăn táng huáng de lĭ yóu]
Saying 'Unloving is the most noble excuse/reason', meaning refusal or farewell based on non-feeling instead of concrete reasons, probably suggesting that saying one doesn't feel any emotion can be the easiest and safest excuse to avoid a difficult situation.