Based on a Cambridge University Study, it appears that the competition over sex is the reason why males live shorter lives than females. The Cambridge study compared males of various species and found that, the more polygamous a species was the shorter the life expectancy was of the male in regards to the female. In these examples, the males ages quicker also.
So, if the dishonesty of cheating isn't a strong enough deterrent to infidelity, perhaps the fact that it can shorten your life, may be!
See the original article here: http://www.livescience.com/animals/071016-male-age.html