I have a very black and white view of cheating. It's wrong. Period.
Is it understandable? Sometimes, but that doesn't change the fact that it is wrong. I'm not going to condemn people for life because they make an error in judgement (cheating vs. talking to their partner or leaving the relationship that don't meet their needs), but I am certainly not going to aid them in their endeavor.
And by aiding, I mean being involved with that person romantically/sexually, keeping their secret, or any other action that would help them along the way.