日久见狗比心不是吗

Literally means 'Over time, even dogs reveal their true hearts, isn’t it?'. This conveys the idea that over time, true intentions or feelings will come to light; just as dogs might not initially show their affection, but will do so eventually with time and trust being built. In other contexts, it could also imply a sarcastic comment that loyalty is found more reliably in animals (like dogs) rather than in people.