Was the guy she cheated on you with asian?
"Hayward can be a #1?"......"Maybe if he goes down to Fort Wayne...DLeague" -ESPN
I'm late to this discussion and probably have little to contribute. I guess the questions I would have if I were in your shoes would be---
a) How old was she when she cheated on you, what were those circumstances? Did she directly break a promise to you? Does she understand she hurt you, and is she sincerely sorry?
b) What was/were the underlying reason(s) she cheated on you (if you can figure this out)? Is this rectified? Are you a good match for each other, or can/should you do better?
Given that she's stayed with you for the past few years, it seems like she really values the relationship, and you should figure out for what reasons she values the relationship and/or what's lacking in it? Do you have real trust now? Is your current relationship just superficial?
I don't think there is a cut-and-dried answer here, and I think you need to try to look below the surface. If you can both come through this as better people, that's positive, whether you stay together or not.
The Jazz play like azz when the J ain't workin'.
Knowing that it was a one night stand based on poor judgement or raging hormones would be better than knowing she carried on with them for several weeks or months on numerous occasions. The first is just physical. The second is emotional and has greater ramifications.