Cheating ? For heaven's sakes, these are Romanovs ! Simply cheating was not the problem here I suspect. People make mistakes, are forgiven and life moves on. Betrayal must have been a more serious insult than some toss in the whatever. After all, VM was pretty sophisticated herself, and as has been mentioned, subject of scandal herself. I suppose we will never know just what it was that alienated her affections, but it had to be more than mere infidelity. After all, they remained married until their respective deaths. And, as far as I know, their children remained devoted to both of them.