Ohhh wtf dad why lock his credit card, you should just let it be and when he use his credit card you will know his location and then you can track him it's basic thing to do smh.
Oh and it would be funny as hell if Hyochan's mom got married with Sungjoon's dad hahahaha I could imagine how Sungjoon reaction will, I think it will be a nice happy ending if they do that.