tap is a acronym for tongue, ass, penis. the sexual encounter begins by the female partner licking the male partner's entire body with her tongue (there is room for experimentation and adventure here). Then the next two steps are connected. the female partner straps on a penis and proceeds to sodomize the male partner (aka will butt-fuck the shit out of him). after this portion of the sexual transaction, the female partner "boards" the male partner. the tap n' board is complete when the male partner "seals the envelop".
*disclaimer: try at your own risk. shit could get weird fast.
yo my man, big cat, you walkin kinda funny - did your bitch tap n' board you last night?