Spoilers
You are correct. Heeseong (puupy) will try his best to come back to the casino coz he was worried his 'brother' might get punished because he disappeared with the money. But he will be betrayed again and sold to a pervert (the one he threw chips in the casino during the 1st chap). Thankfully our ML was fast and he was aved. There was an attempted r*pe but nothing happened coz of ML. His 'brother' is trash. Not sure if it was mentioned already but they are not biologically related. They only met 5 yrs ago when he was taken in by his 'brother'.
spoilers
he was very innocent my heart was breaking when there was a flashback to when he was a kid.
he was very sickly and weak so his family left him they told him to wait and he did! they never came back! and it's not a misunderstanding, his parents really did intentionally left him. im tearing up again writing this. that's why he's clinging so much to his 'brother', coz he is his only 'family'.
he was so hurt to the point he said that he understood why his family left him coz he's weak and sickly but he didn't understand why his 'brother' betrayed him when he did his best and hardest all those 5 years. he thought it was his fault he was weak and sickly. poor baby, my heart.
spoilers
not really, his 'brother' was never a good person. They took puppy on a whim and kept him coz he's pretty. He already has plans on how to use him ever since he was picked up. Most of his earnings as well goes to his "brother' for 'safe keeping' and to help his 'brother' pay off the debts. these debts are the 'brother's' only coz he has gambling addiction. And puppy only helps as pay back for picking him up. when the 'brother' said that this will be the last job and that they will get out of the gang, that was meant for the 'brother' only, he planned to leave puppy to get the blame for everything while he gets the money and freedom.
Idk but, my guess is that hyung is the one who hired those thugs to hire you to make you not be able to be free...