When someone has the worst case of blue balls, that they spontaneously ejaculate on there keyboard whilst in voice chat with people, hence The Dirty Jay.
flea: "omg did you hear that Kevin did The Dirty Jay! on Discord last night?"
The act of eating a girl out while she shits on your chin, saidshit will stick to your chin making it seem larger like Jay Leno's Chin.
Bratcher- Man i was tasting some cunt nectar from the goregous girl this morning and she shit on my chin! The worst part is when i backed away it stuck to my chin!