If you were to find out that your partner cheated on you, how would you react to/deal with the infidelity (the hurt, the anger, the betrayal)? And how do you forgive something like that? Is it possible to move on and learn to trust each other again? Or do you give up with no more chances and take a zero tollerance policy no matter how much you love the person?

#1 you have to remember everyone is human and has made mistakes. No one person is perfect. Try to put yourself into THEIR shoes and view yourself from their perspective. Walking away every time there is a difficulty is not how an adult deals with things. Would you want them walking away if YOU did something stupid you regretted?

Now assuming they did regret their actions consider that they did come to their senses and realize they understood they had a better person with them (meaning you) than they previously believed.

People cheat on their diets, they cheat on their taxes and they cheat on tests. None of those involves sex. Yet sex is a more compelling urge than any of those. So it isn't at all uncommon for people to cheat. That's why if you find a person that doesn't cheat, that's a keeper. Once the trust is broken it can never truly be completely restored. Forgiven perhaps but not restored.

I feel there is a huge difference between a one time indiscretion and serial affairs AKA an ex-US president is known for. The Former is likely driven by events, and disagreements and the later is a serious character flaw.

I assumed this was the former not the latter. If it was the latter I would not be forgiving.

You need to understand that if someone cheats on you or you cheat, it doesn't nessarrey mean it's that person's fault.
When you are in a relationship/marriage, you need to love respect and always communicate with your partner. When you are not in a happy relationship people tend to find someone or something that makes them feel better. That is cheating on the partner or other activities. I'm not saying all people cheat but most people if the situation comes up and they aren't happy in the relationship they are in, they will cheat.
I think if my Hubby would cheat on me, of course I'd me in a lot of pain, but first I will try to understand why he did it. I'm not saying that this is what I WILL do if he cheats, I'm just saying that's what I THINK I'll do. Who know's maybe I'll never forgive him, But like others have said, everyone makes mistakes.
:)

I have been in this situation, and I am still with the person who cheated on me. There are times where I really have a hard time trusting him, but as time goes on my heart grows stronger and I just have more faith in our relationship. If you believe that they sincerely are sorry and they continue to prove that they aren't the cheating type then I would give them another chance before assuming that it will happen again. If you can see yourself growing old with this person, then just know that mistakes do happen. There will be times where it's hard for you to trust, really hard... but if you make it through that low point, the next time you start to question him it's a little bit easier. Let that person know EXACTLY where you stand and tell him that you are going to be very cautious and gaurded. In my case, I am REALLY open during the times I feel hurt by the situation that happened a while back. I open up to him and tell him that I am struggling with thinking that he might be up to something. He now owes you the reassurance if you are going to give him another shot.

I say you can never be 100 % without doubt that they won't cheat again. Once the chain of trust is broken, it is always broken. This is one mans opinion.

Thanks for the responses. :) Though, I wasn't asking for me personally, but rather I know someone who is going through this. I am not. Which is why I left it so general and didn't go into any personal details.

But I know if I *was* in this situation, although I agree with those who said people make mistakes - I am well awear that NONE of us are perfect - but me personally, I tend to forgive but never forget. And if I were to ever be cheated on by my husband, although I have a love for him that runs deep and always will, I would forgive him but never again be able to trust him and that in of itself would be the end of the marriage. But we could probably move forward with a friendship after the pain healed up some. I also think that if you let someone make such a huge betrayal, they apologize and you take them back, it lets them know that they can do it again. If you set a boundary in the beginning of a relationship that infidelity will not be tolerated and then you go back on your word, and let the person get away with it anyway, what's to stop them from doing it again?

That said, I hope I am never in that situation.