A new study may explain why some men are still single.

The study, by British mattress maker Ergoflex, says the average single man changes his bed sheets just once every three months. Compare that to single women, who change their sheets every two weeks on average, according to the study.

Couples appeared the cleanest, changing their sheets every two weeks. The clean advantage for married couples should go to women in the relationships; they do 81 percent of the washing, according to the study.

The survey of 2004 people also showed that:

— 17% of single men admitted that a date had been put off by their dirty linen

— 49 percent of the worst offenders thought their bed linen habits were acceptable

— 19% just didn’t care.

Cleanliness concerns seem to get better as we get older: According to the survey, people between 35 and 50 years old are the most likely to wash their bed sheets each week.

Read more about the Ergoflex survey here.