Marriages fail because of cheating.
Happy contented couples are happy because no one is cheating. The cheater destroys the happy family because they think with their genitals and not their brain.
I disagree with the above point, as one person in the marriage may not be happy & contented and will cheat because the marriage is or has already failed as far as they are concerned....Otherwise they would not feel the need to cheat in the first place. One may THINK the marriage is working, but if the other dosent or love is one sided, then its clearly not and one wouldnt run into the arms of somebody else.
The cheater destroys what may already have been destroyed in their mind. A marriage is two sided.
Therefore as we have different opinions on this matter.