This happened to many times when I already have huge profit such as x2 to x5 of my bankroll. I usually hangout out for more gambling but place only small bet on slot games. This small bet turns into increasing bet when losing badly u til I already buying bonus that keep losing too until I bust all my bankroll.
If you win already you can take back to your original bet so you won't get too greedy sometimes people keep testing until when and where they can still manage to hit a jackpot or profit so just one lose isn't enough to them to consider that they need to get stop for a while and take a look with their balance or situation are they still winning or not. Personally, once I win a large amount I will call out this for a day and make another game for next day so I don't get carried away when I win and lose another money because seems like it slipped only to my wallet and get away because of wrong decision making and making more greedy to urge to earn back those losses or urge back to play more hope to win large pool again.