n. a display of lights and touches administered with glowsticks, flashing LEDs, etc. by a person to another who is under the influence of alcohol or drugs, particularly ecstasy. This is done in order to enhance mental stimulation provided by the vision-altering substance.
The Texas Light Show is the art of placing a Roman Candle in the rectum of a companion, then lighting the fuse, thus causing the firework to shoot out of the buttocks of your companion
When you creep into a girls room with the lights off and ejaculate on her face, while she is still sleeping. When you go to leave the room you flick the lights on and off and yell "lightshow!"
John snuck into Jenny's room last night and ejaculated on her face while she was still asleep. As he snuck out of the room he flicked the light switch on and off and yelled "lightshow!"