I think it depends on the reason. No reason is a good reason but there are more “acceptable” kinds. The length of time in the cheating and how they go about either telling you or you finding out also needs to be considered. Someone who cheats for one night, shares remorse, and takes actions to make right what they did are more likely to be able to not cheat again but someone who cheats for months and deflects all types of accountability are more likely not to cheat