I've been married 2 years but we moved in for over 7 yrs now and I've never cheated, not even when shit has gone bad with no sex for months, sister's been with her guy almost 10 years, no cheating, cousin also 13 yers, no cheating, so we're still out there bro there are still committed and respectful women out there, gotta filter through some trash to find the treasure, dont let this woman set a precedent for future women
Be prepared for a TON of scenarios ranging from excuses, to fake tears/apologies, maybe a fuck it kinda attitude and she'll start pining her whorish behavior on you, etc, personally I couldnt walk out of the relationship with her thinking I dont know, I'd want her to know I know so she doesnt think she can get away with shit like this, I'd dump her in a way in which I dont even leave room for explanations, just tell her I know, ask her not to bother explaining and remind her why I'm so great and how they should now go fuck themselves, be the one who got away man, she doesnt deserve you.