I doubt believe once a cheater always a cheater. Sometimes you have oppurtunities and you wanna be an oppurtunist. But context determines her values. If she's been with you a month and an NFL player comes and sweeps in, I can't be too mad. That's an L you gotta take and KIM. Now if she's been with you for 6 months to years, and that same ish happens, she's wack af.
Even then it says more about that persons morals than their worth, especially if the person she cheate don with never knew. Get over mentality, have you cake and eat it too mentality, and 1up mentality. Always looking to upgrade. So for me cheater or not, women with those traits get grouped into the too unstable category