When you are preforming anal sex and go a little to deep. This deep penetration may cause you to hit a special spot. When this spot is touched she will start defecatingeverywhere. When this happens you have flipped the switch.
Bailey: "oh my god Gina I'm so horny and Travis is out of town.."
Gina: "girl you've gotta trip the switch."
Bailey: "what's that?"
Gina: "tripping the switch? Like fucking yourself?"