Good on you! For others who may be curious: Australian/British slang... To 'suss-out' is to investigate. Someone's actions can also be 'suss', as in arouse suspicion or be suspect.I had to look up sussing.
American popular culture washes over the rest of the English-speaking world. We're familiar with your accents, your slang, your artists and even your politicians. It's almost entirely a one-way street. We even adopt your expressions as our own. I'm fighting a rear-guard action to keep my children (nine and ten) speaking Australian English. In today's on-line world, it's a battle I will lose.