Is lack of sex the number one reason men/women cheat?
No, the #1 reason men/women cheat is that they’re unprincipled and/or pleasure-seeking. Blaming cheating on the spouse you’re cheating on is just a way to deflect responsibility for your own behavior onto others. And people who do that are the very people who tend to have weak consciences–because they don’t feel guilty for doing bad things, since they have found it’s easier to blame it on others. Why accept the logic of the wrongdoer? Plenty of people don’t get enough sex, but don’t cheat.