Plenty of cheating spouses do return. but sometimes one needs to consider the pros and cons of a situation. Especially when there are no children to consider. In a situation where one is dating, or there are no children (human that is, although I do think of my dog as "almost human"), trying to keep a family together is less of an issue. Some "pros" might be a relatively good history, the person is remorseful and truly wants to be with you, etc.... "Cons" might be... continues to lie, lied in the past, moving on might be easier than forgiving, etc...
All the advice about GALing is good. Another thing, all decisions should be made over time. Breaking it entirely apart, or reconnecting should be something thought carefully about over a period of time. Give space to work through anger and spiraling emotions.
There is no arriving, ever. It is all a continual becoming.
