Hey Blue and Gretchen...
Once a cheater, always a cheater may not always be true. Love and forgiveness is a huge part of life. We all make choices, some good and some bad...And yes, unfortunately some make really BAD mistakes. Doesn't mean that they are a bad person, just means they were not thinking and put their own needs first before their spouse. It's wrong, but is forgivable with lots of love, support, trust, honesty and marriage councilling.
She does deserve better, but until she is in a better thinking place, no harsh decisions to actually END it all should take place.
Some marriages do work out and go on to be even better...Some ofcourse, don't and end up in divorce.
Blue, I hope you're hanging in and doing OK. Post back soon.