Size really does matter! Women are MORE likely to cheat on men with larger penises, new study claims. Study examined 545 women in Kenya, of whom just 34 cheated on husbands. Those who did cheat told researchers they disliked pain and discomfort. Research was published in the scientific journal PLOS ONE. The study of fishermen found those with larger penises were more likely to be cheated on. The male fishermen who had been cheated on were better-endowed than those whose wives did not have affairs, the researchers said. The better-endowed husbands had fully erect penises of around six inches, while whose whose wives were faithful had erect penises of around five inches.