(n.) A variation of "nuts" (testicles) that females may have which represent that the girl has another person's complete attention to them. This type of attention usually refers to when a girl has strongly commanded another guy (or girl)'s romantic affection, but can also be used for when they have other friends/followers consistently demanding that female's attention. The word derives from "hypothetical" and "testicles."

the whale tail is the shape formed when a g-string rides up high over a womans trousers