My wife had an affair when she flew back home alone and now expresses anger at ME, because I said in response to her question about me trusting her to me that "I don't trust anyone".
I explained to her that you don't cheat on someone, have them find out despite your lies and sneaking and then expect them to expose this 100% trust for you.
Trust is earned, and if it is destroyed, it needs to be re-earned.