Don't do it.
Most men who cheat know they are cheating and that it is wrong, they just choose to do so anyway and live with their consciences. There have even been studies that show that there is even a possible genetic predisposition towards infidelity in men. I heard about this from a childhood friend I reconnected with a few years ago. His grandfather cheated, so did his dad and uncle and so did he. Screwed up every relationship he had until he made a conscioys effort not to. Now he's married and he hasn't cheated, but he says he has to make an effort not to. Bottom line, they know they have a problem.
Women who cheat, though, also have a need to feel good about it. It just simply can't be their fault. It's always your fault for doing or not doing something or the "relationship just wasnt working," otherwise she wouldn't have felt the need to throw a leg for some dude that made her taco tingle. They are chronic RATIONALIZERS, plain and simple, and those are the ones you gotta watch.
Those are the crazies....The psychos capable of anything and blaming it on some complete bull****. Like shotgun you in half because she thought you were "verbally abusive" or drown all 5 of your kids in the bathtub while you are at work because they overwhemed that day her or stab you 50 times and shoot you in the shower because you broke up with her or (my personal favorite) despite being one of the most highly educated, physically conditioned, and emotionally stress tested women on the planet, she might throw a knife, rope, a shovel, and a bag of lime in her trunk, and put on a diaper so she doesn't have to stop on the 12 hour drive to kill her astronaut collegue because she thinks you two might be having an affair. Those are all true stories.
I took back a cheater once and it ended badly with her cheating again. I got blamed, of course. And it was a waste of several years of my life. Given the big picture, I think I got off easy. If you take back a cheater, cheating on you again is the least of your possible worries, imo.