And I'm not (specifically) asking about criminal acts, though those can be valid answers as well. Societies and cultures can frequently agree on what actions are harmful and damaging to either the social structure or to members of it and label those as high-crimes or capital crimes (such as murder, kidnapping, sexual assault, or even acts of apostasy or criticizing those in power or the structure itself). So, feel free to list those if they are the ones that immediately pop into your head. But what I am more interested in, are the non-criminal acts that you as a person would find to be "unforgivable" especially if that action was directed at you, or someone you care about. The reason that I ask is I had a recent chat with a few folks and a subject came up (I won't list it as that might skew some folks comments) and our group was split 50/50 as to whether this particular occurrence/event was something that they could forgive or that they would not be able to forgive someone (or anyone) if they did it to them. If a comment intrigues me, I may ask you to explain or clarify. Please don't take that as me doubting, ridiculing or challenging your answer or view. When I ask questions, it's usually because I don't know or understand something and I want to expand my knowledge on the subject. Thanks for your time and I look forward to hearing what others think. 5/12/16 Edit: Thank you everyone for your serious (and grin/cringe inducing) answers. Much like the conversation that put this question into my head, when it came to non-criminal acts, the friends who I were speaking to would list infidelity as unforgivable if they had a list, and that one was usually at or near the top of their list.