Chemistry tells you how they make you feel. Character tells you how they’ll treat you when it’s inconvenient.

Chemistry is real and it is also information about the good moments only. It tells you nothing about what happens when helping you costs them something, when they are tired, when nobody is watching, or when you need what they do not feel like giving. Character is the part that shows up then. The two are independent, and people often have one without the other.

Watch how somebody behaves when it is inconvenient rather than when it is fun. How they treat people who can do nothing for them is usually the fastest read available.