Before you think about cheating on your lover ask yourself, "how crazy is my lover?"
If the answer to your question is ANYTHING that might scare you, just stay unhappy. (kidding, just leave the relationship but don't cheat on someone.)
Cheating on your loved on can really ruin their life or yours, depending on who your lover is so let's avoid that.
Now, did her husband deserve this? You be the judge.