No matter how deep you sink into the ocean of despair, things can always get worse.

But really, I'd say you should tell her husband if she keeps doing that. If he wants to go insane and choose to ignore her for eternity and beyond, that's his problem. By NOT telling him, you just improve the chances of having her cheat on someone else, which will hurt her husband a lot sooner or later. And he WILL find out eventually if that's the case. People make mistakes.

"Stephen Wolfram is the creator of Mathematica and is widely regarded as the most important innovator in scientific and technical computing today." - Stephen Wolfram