“Reading between the lines” is a practice that can generate a lot of misery. Besides I'm not sure that it's even possible to really do such a thing
You know how it goes, right? Someone you care about acts in a way you don't understand and you are hurt or insulted. What causes your uncomfortable feelings? Is it their behavior? Isn't it more likely that your unhappiness comes from what you “read” into their words or behavior?
When we “read between the lines” we project onto another our own interpretation of their behavior. Why would we ever choose to attribute a reductive meaning to something someone else says or does?
Maybe we're right, maybe not – who can know for sure? But when we give negative connotations to someone else's actions, we just set ourselves up to feel bad. Even if they do happen to be thinking exactly what we project them to be thinking how does it help us to know it? After all, what does their opinion of us really have to do with us anyway? Ascribing such limiting thoughts about ourselves to another seems such a mean spirited way to treat ourselves! It can only lead to extremely low frequency feelings!
Besides, how in the world can we really know what the thinking is behind someone else's behavior? What a wasteful use of energy to try and second guess what they might mean by the things they say and do – and to what end? What possible good can come from attributing a worse-case-scenario to their behavior? All such thinking accomplishes is to generate verification of our (possibly mis-) interpretation of words and deeds that leave us feeling bad.
No, It's not our business to figure out why someone else does what they do … but it is our business to look at our own motives for trying to figure out “the real meaning” behind their words and deeds.
Why not simply accept their behavior at face value instead? It's the kindest way to treat them AND ourselves.