That's when you tell this to your girlfriend, she will ask you to leave gambling as it only provides temporary pleasure while she can provide you with permanent pleasure
Better to ask her what is the exact reason she wants us to quit gambling and then we will be in a better position to respond.
So what is your response to your wife? Do you agree with her or did you decrease your gambling activities? If you do not listen to her, I am sure she would usually fight with you when she sees you gambling. Maybe you gamble only when she is not near you so she would not know?
Since you have a practical experience where your wife asks you to stop gambling, it will be interesting to know your and her reactions to this matter.