It is very difficult to realize that your spouse can deceive you. I am familiar with this situation. I recently learned about my wife's betrayal. I also spied on her for a while. Here
https://www.igeekphone.com/the-7-best-ways-to-spy-on-your-cheating-spouse/ I found some tips on how to do it discreetly. And I was sad to realize the fact of treason.