by Jae MoniqueDo you think your partner is cheating? Cheating and infidelity are never found out in many situations. Men are more likely than women to cheat. This is the must have guide for women who are married, in a relationship, or about to get into a relationship. There are about 30% to 60% of marriages that have had some type of extramarital affair during their marriage. About 3% of children born are a result of an affair. Cheating and affairs are more common with people who are under the age of 30.