According to Neuman, the lesser frequency of sex among couples is owing to common problems of daily life such as paying bills, kids getting sick and even lack of sleep.
He based his findings on a research experiment that involved 400 women who were considered happy or unhappy.
The aim was to discover the number of times a couple must make love every month to be happy.
"Emotional betrayal through a virtual affair can be even more damaging to a marriage than a physical affair," said Neuman, author of the book titled "Emotional Infidelity: How to Affair-Proof Your Marriage and 10 Other Secrets to a Great Relationship."
It is easier to counsel a couple wherein the man or the woman had random sex with a stranger than if one of them have found a best friend on the internet even if they had not touched.
Virtual affair "is a much harder thing to heal in a relationship because the emotions have left the marriage and gone into the hands of someone else," he said.