Flick the bean is a slang phrase that is used as an alternative when referring to female masturbation. Generally, the phrase is used to describe external or clitoral masturbation, as opposed to vaginal-based masturbation.
Flick the Bean
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Rather than using the term masturbation, the phrase flick the bean might be used to refer specifically to female masturbation. The term flick is used in place of massage, while bean refers to the clitoris. So, to flick the bean can be translated to massage the clitoris, or refer to external female masturbation in particular.