The act of fucking a girl so hard, from any position, so long as the balls smack the female to the point that there is an unmistake, audible, and loud skin on skin popping sound resembling the sound of a breaching whale's tail smacking the water.
the portion of a thong that shows above the pants in the back, it resembles a whale tail. whale tail- when a girl bends over and previously unseen whale tail shows, she is whale tailing, you the one who sees it have been whale tailed.
When Annette bent over half of her thong was visible. " Yo, Annette, you just whale tail(ed) me, son!"