Some women often fake their orgasms in order increase their chances of actually achieving one.

The researchers found that while altruism was the most common reason for faking an orgasm, many women also revealed that they did it to increase their own arousal. Writing in the report, which has been published in the Journal of Sexual Archives, the researchers said that their study provided quantitative evidence that women faked orgasm for selfish reasons as well.
“What is unique about the Faking Orgasm Scale for Women is that, for the first time, we have quantitative evidence suggesting women may also fake orgasm for far more 'selfish' reasons, like increasing their own arousal. I view this strategy as one of the many 'tools in the toolbox' women may use to enhance their own sexual experience”, lead researcher Erin Cooper said.
Source-Medindia