Complicated
I think in some ways it'd be different - she thinks any sex outside is cheating where as I just see it as fun
So I don't consider it cheating when I see sex workers but any sex she had she would go into it considering it as cheating from the outset
Flip side to that is I know she'd think what I do IS cheating so that's no excuse for me.
All up it'd depend. If it was a long running "emotional" affair (is she dated and slept with the same guy a few times or me,) I'd leave.
But if it was a one night stand I'd other get upset (some of that for show) then move on