It is true that gamblers change their mindset after winning in gambling, because they forget the past and later they have a desire to win more. If there is a role for giving money in gambling, then after winning, the gambler changes his mindset and later forgets to keep this promise. He fails to follow this incident in turn, but some gamblers do such a disrespect.
However, in my life, I lent money to a friend while gambling, later that gambler faced losses while gambling. Today, it has been more than two years and he has not paid me back, and since then I have not given him any more loans. The gambler forgets the promise he makes at the beginning while gambling, and later he does not keep it.
They think that now is the time for them to recover their losses so that makes them keep playing gambling without think that their winning is just temporary. No one will know if they can win in the next rounds but they can loss in anytime without taking too long. He can forget about his promise and not give the money to other as his promise because he thinks that he will make more money first and then he will gives that money. But then he loss his money in the next rounds which makes him can not gives the money.
No wonder if you have that experienced because I have the same experienced like you but I am not think too much because since he borrow my money, I decide to give that money without wanting to ask the money back. I know he will not come back to me especially if he have the money so I don't takes too serious about that.