'Once a cheater, always a cheater' is a phrase born from stories like this. It's the cautionary tale of our worst nightmare. If someone is already willing to cheat and lie, what’s to stop them from doing the same to you? In the end, everything tends to come full circle. For this woman, just trying to move on with her life, things got heated quickly. Cheating is always a huge red flag, a bright, glaring "no" in any language. And when it's happening in the workplace, things inevitably get messy.…