When in doubt, do a simple cost-benefit analysis!
The (Simplified) Cost-Benefit Analysis of Cheating
Assumptions:
1) Each benefit has a value of 1, each cost has a value of 1
Benefits:
1) One-time sexual gratification
Costs:
1) Loss of a lifetime of companionship
2) Loss of a lifetime of sexual gratification
3) Betrayal of trust
4) Loss of self-esteem
Conclusion:
Total benefits (1) < Total costs (4)
The total costs of cheating are greater than the total benefits of cheating, and as a result, a rational person should not cheat. And, being the rational consumer/economist that I am, it would be illogical/irrational for me to cheat; therefore, I will NOT cheat.
It really IS that simple!