wanted to work on "us," I'd be there. I don't know at this point if I'd be able to forgive or trust, but I'd try.
Have to have both to make it work. Example...let's say she is "running late" at the store, caught up in traffic, whatever - would a smidgen of doubt enter your mind? If there is even a little, then trust isn't there. And being in a relationship where you don't fully, 100% trust that person is, well, ridiculous, to put it lightly. The question is, how could you trust someone who so deceived you as to sleep with someone else? Ultimate disrespect.
There are moments in this life when you are so confident in the rightness of your actions, that not even for a second do you consider the option that you might be wrong.