Does size of your penis worry you a lot? Stop thinking and get on with the act as a study reveals that women are more loyal to men with 'smaller' penises.

A team of researchers from the US and Kenya found that there was a strange link between the size of the penis and infidelity in a marriage.

Contrary to what many men may assume, they found that men with bigger penises are more likely to have wives who cheat on them.

"The reason is that women experience more painful sex when their partner is 'big'. That prompts them to seek another partner whom they may have more pleasurable sex," the study noted.

The study was conducted among the fishermen community in Lake Victoria in Kisumu County, Kenya.

One of the women said that she had to look for another man with a "smaller one" so that she could "do it in a way" she could enjoy.

According to the study, published in the journal PloS One, other possible reasons of a woman's infidelity in a marriage include denying her a preferred sex position as well as domestic violence.

Extramarital affairs may also happen when a woman is sexually dissatisfied, the study, reported by International Business Times, said.