A survey in the US has found that men think they satisfy their partners more often than they actually do.
85 per cent of men said the last person they slept with had an orgasm, while just 64 per cent women agreed, revealed a National Survey of Sexual Health and Behaviour.
The study found that men are more likely to orgasm when sex includes vaginal intercourse, whilst women are more likely to orgasm when they engage in a variety of sex acts.
"Our main point is that sex is more than just vaginal intercourse," The Daily Mail quoted Michael Reece, director of Indiana University's Centre for Sexual Health Promotion, as saying.
"While it does appear to be the most common behaviour ... many people are being diverse in their sexual lives," he added.
Around 7per cent of women and 8per cent of men said they are gay, lesbian or bisexual and some 41 different 'combinations of sexual acts' were identified.
Some 80per cent of 14-17-year-olds - 80per cent of girls and 69per cent of boys - said they wore a condom during sex, compared with under half of adults who enjoyed casual liaisons.