At the risk of stirring up a hornet's nest...
On the wives' part, by being less egocentric and learning how to share their love and possession with others, especially other women

.
(The world's woes in a nutshell arises because of the ego's inability to share anything and everything).
My suspicion is that there are many wives who submissively accept the situation so long as their husbands do not forsake their duties and responsibilities towards the family, including the wife. Where the wives cant accept it, the secular law(or otherwise) kicks in to assuage the situation. That is the price that parties must pay for assuming, idealistically, that spousal love lasts forever.
And when the wives do accept, the family unit survives.
But in the end, if you think about it, nothing lasts forever

Hey, so what's the big fuss all about ?
IMHO the coping has been made difficult for most couples coz' both tend to pander to society's standards, which frowns on such unenviable situations. But I am wondering who set these standards, as standards to live by, in the first place ?
Quite certainly it's not the powers-that-be(the lawmakers); because if it were, infidelity would have have become punishable in most civilised nations by now.
I am not advocating "free love" here, but "responsible love" and facing facts "after the love is gone". If the last were to happen just move on and continue discharging the responsibilities dutifully and, if possible, lovingly.
Love & Peace .