Light is on

When someone is ready to date or looking for a committed relationship.

"I think you should flirt with him, his light is on!"
"Men are like cabs. When they're ready to get married, they turn their light on." -- Sex in the City

Light is on by geistweg January 25, 2015

The light is on but nobody is home 

A common phrase used to refer to someone who's perception is very, very slow. An imbacil for example. Someone who just can't understand.

A: Excuse me, what time is it?
B: Time for you to go home and play with soap!
A: But my mom will be angry if I waste soap?!
B: The light is on but nobody is home
C: Kalevet!!!

The light is on but nobody is home by wandman September 1, 2005

Light dawns on Marblehead 

When something obvious is finally recognized by some stupid shit.

It might be a good idea to wear a mask after Donald Trump caught COVID-19.
Ah, light dawns on Marblehead!

Light dawns on Marblehead by Beat Service October 2, 2020

Light dawns on Marblehead 

(Of Massachusetts origin, reference to sunrising on the seashore over Marblehead, Mass)
Sudden realization of the obvious, the “Ah-ha!” moment. Sometimes with a smack on your forehead gesture for emphasis.

“Well D’uh! Then light dawns on Marblehead!”

Light dawns on Marblehead by NoPrizners September 29, 2021

Auxiliary light is on. 

Auxiliary light is on.

During the Russo-Ukrainian War the saying "Auxilliary light is on" came to mean: "you're all about to die." In 2022 drones purchased at toy stores killed or wounded groups of Russian soldiers after being armed using the auxiliary light button on the controller.

We're in position...grenade away. Lads, the auxiliary light is on.

Auxiliary light is on. by yhjuyjsx October 13, 2022

light my tits on fire

When a stripper splits a paper match & affixes it to her nipples & then lets a voyeur light the match.

Laura was the one who did this interesting trick of letting the customer light my tits on fire.

light my tits on fire by Starchylde May 20, 2016

light our balls on fire 

something you would say after an another individual thinks of a dumbass idea.

Timmy: Hey guys lets go to the art show.

Justin: Or we could light our balls on fire.

light our balls on fire by Don L February 18, 2008