communication

a guy with his male friends 

a girl with her female friends 

guy and girl likes each other 

guy doesn't know if girl likes him 

girl doesn't know if guy likes her 

male friends knows that guy likes girl 

female friends knows that girl likes guy 

if male friends and female friends communicate with each other 

that guy likes girl and that girl likes guy 

then male friends can communicate to guy that girl likes him 

and female friends can communicate to girl that guy likes her 

and then both guy and girl knows that they like each other 

so guy and girl dares to initiate contact to organize a date