I might, however, be tempted to imply that I know she is on the pill, and having/had a PA with guy(s) from work. Yeah, I know that would be a bad idea, but it is driving me crazy to not confront her about stuff I know is going on.
Yup, THIS ^^^^^, is what you need to hold yourself on.
The early stages were best dealt with this attitude: -She is a friend with issues.
Try to re-frame it like that, though she is your wife, she is a free human being, free to make her own choices, good, bad and ugly.
My other two SOPs are: -"Aloof,yet available" -STFU (they "tell" you so much more when you do this).
Good luck!!
In the depths of winter, I finally learned that within me there lay an invincible summer. - Albert Camus
Uncertainty is the very condition which impels people to unfold their powers.-Eric Fromm