
ok so I am confused... he is con artist or not?

I don't think so, at least not in the sense that he's scamming anyone. He seems to be doing exactly what he's selling (being a sex teacher). And he seems to actually be some kind of teacher since he works at an Academy. His motive is unclear so far but I assume he's either doing it mainly for extra money (cause it shows he lost a lot gambling) or sex cause he thinks the guy is cute. But at the start it seemed to be semi a joke with his gambling friends. But in a way, he is taking advantage of naive people. And maybe he has done other cons in the past - that, we don't know yet.
He really need to let seok il go if he like minhyuk hyung so much