The BEST way to deal with that is to do NOTHING. Don’t investigate, don’t ask, don’t demand to know why she’s out late, don’t stalk, don’t search her phone. The reality is that, IN HER HEAD, an affair is justified. So once you find out and tell her you know or make demands she end it, most likely she will feel threatened. She will probably say some typical WS bullshit like “This is why I had to leave you.”
The only way anyone ever snaps out of an affair fog is if they simultaneously work out FOR THEMSELVES that it’s the wrong thing to do, and simultaneously stand to lose everything suddenly.
If she admits to an affair, say nothing. No arguing, begging, pleading or crying. If you seem unaffected, it will confuse her. Then, the next time she leaves the house, move all her stuff into storage. Like everything! Then text her “I no longer wish to share my life with a cheat. Your stuff has been moved to storage at xxxx. The code to access is xxxx. My lawyer will be in touch.”
If she’s having an affair, that’s the best chance you have IMHO of turning things around.
Don’t do or say anything the old you would have done. Do the opposite. Confuse her. Bring female friends (platonic) over for beers. Go out and party. Imagine her being around is a bit of an inconvenience.
99% of men (like me) who come to this site are submissive by nature, or have been beaten into submission by someone threatening to leave us. Men who are confident, outgoing, attractive and confident in themselves don’t come to this site - because if a woman is leaving them, they say good riddance and let them leave.
Please work on your own confidence and self love with a professional counsellor. You deserve someone who treats you well. And at the same time with your counsellor, identify what you did wrong in the marriage, identify your own faults - and prioritize the hard work to fix them.
Good luck!
"What is best for my kids is best for me" Amor Fati Link to quotes: https://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2879712
