And if you both hadn't been physical for months, or even years, ummmm - each situation is different. While generically you are correct, I think that there is more room in this one for "give" than say the abuse ones (def no no to both physical and mental abuse).
As to Smowball's comment, a lot of us haven't experienced the gamut of situations that you mention. Thank Goodness. I have experienced the cheating side - and we worked it through - for a while. It contributed to the divorce but that was for other reasons mainly.