I believe there is some truth to what you said. Most men would leave a woman if he knew she were cheating on him. Women are groomed to be disappointed or hurt by men in our society. So much so that a lot of women are told "Men are no good", "Men are Dogs", or "All men are liars".
Some of the biggest hit songs and movies are about how a guy hurt a good woman and in the end comes back begging her to forgive him. The woman takes him back and they live happy ever after.
There are florist shops with the name "In The Doghouse". The majority of greeting cards for men to buy women start off with "I know I don't say this often enough..."
How many hit songs or movies do you know of where it's the other way around? There are no (female versions) of songs like Boyz II Men "On Bended Knee", Tyrese's "Stay", Usher's "Confessions Part ll"...etc
Last but not least men are very visual creatures. Picturing their woman in numerous postions with another man or her doing things to another man are tough images to lock in the back of their mind.
Personally from my point of view I don't give second chances and I don't ask for second chances either.