Sometimes people have problems that they're very reluctant to discuss, even with their spouses and physicians. Impotence is one of those issues. It's only my opinion, but I think that communication is crucial to maintaining any sort of relationship and/or deciding whether or not said relationship is mutually destructive, beyond repair, and should be terminated.
I don’t know, but people probably aren’t going to get help talking to strangers on the internet. I can only say that almost always when someone I know got divorced I was not surprised and usually both were sabotaging the relationship in some way. AND you cannot tell either party anything because they are sure none of it is their fault. Life is complicated, relationships are complicated and marriage is hard. Communication is important but the best preparation for a good marriage is to have grown up surrounded by good marriages.