The act of shouting out everything you do during the course of a sexual encounter. The key to the successful execution of "The Billy Mays" is to, at a moment of particular intensity, shout "The secret's in the ___(insert sexual act, nickname, or body part here)!!"
"I'm putting my thumb in your butt!!!" =The Billy Mays
"My shaft is halfway home!!" =The Billy Mays
"The secret's in the money shot/penetration/honey hole/meat basket!!" =Perfect Billy Mays