Watch his eyes, the way he talks with people and how he behaves. Read his body language. Does he look right at people when he talks to them? Is he always joking around or can he be serious if you have a serious question.
Really, it's just a matter of getting to know people so you can get a read on their language and their behavior.
You don't and until you are sure, keep not one, but both legs closed.
Teenage guys got hormons going everywhich way i doubt you can find a teenager guy sincere
if he opens a door for a girl that's nice.
By his actions .. Not his words. Being polite does not necessarily mean he is sincere but it does speak for his character if it is genuine. . Being polite .. especially overly polite can be a manipulating tactic.Â
There is a certain amount of witnessed behaviours over a reasonable amount of time that helps us to take an educated gamble on trusting someone's intentions.
As Forrest Gump might say, "Sincere is as sincere does."
And there's a good metaphysical principle behind that:Â "First you are and then you act."
Think about that for a while.
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