If what you and your partner do between the sheets is no longer doing much for you, but you're faking satisfaction for appearances' sake, you may be fooling ... no one. A study of 84 heterosexual couples by researchers at Canada's University of Waterloo has found that men and women in a relationship "have fairly accurate and unbiased perceptions of their partners' sexual satisfaction," the study's lead author says per the university's site. The study's participants were either married or lived together, and were asked to report on their sexual and relationship satisfaction, sexual communication, and ability to recognize emotions—as well as that of their partner.
The study found that men and women were pretty accurate in gauging their partner's satisfaction level; no significant gender difference emerged, though the study notes that "one sample t-tests" showed men actually "slightly underestimated their partners' levels of sexual satisfaction." Two factors apparently affected accuracy: communication and that emotional recognition. Though researchers found that good communication on sexual matters boosted the understanding of those levels, "a person could still be fairly accurate in gauging his or her partner's sexual satisfaction if he or she was able to read emotions well." (Another recent study found that some women fake orgasms for ... pleasure.)