The average happily married man wont cheat..... well, what that really means is that they wont run around looking to cheat.
If however an opportunity to cheat is thrust upon them, then it becomes a different story! The more intense, the temptation, then the more likely they will cheat.
But honestly, you can say the same as above for women as well.
Anyhow, if a man or a woman wishes to remain faithful, it requires more than just a loving relationship at home, it also requires a degree of wisdom to avoid temptation, that is the bottom line!