Who is more likely and frequently the culprit of spreading STD's/STI's? Men or women?

In anecdotal research, women tend to chase a much smaller percentage of men, so men like the quarterback of the football team have many more partners than the average. However, men will sleep with anyone that moves, or has recently moved. Therefore if you graph the results you will see that among hetrouals, men and women are equally to blame, otherwise there would be no spreading. Think about it.