Pre Ketchup cum is the almost see through substance that comes out the average ketchup bottle whenever it's poured onto your favourite meal or your just really thirsty
Pre Ketchup Cum is something that 9/10 average human beingsexperience over their lifetime
The watery bit of ketchup that comes out when you go to use the ketchup but the bottle hasn't been shaken up or it has been left a while without being used. This leads to a puddle of watery ketchup being left seeping onto your plate and probably on your hands.
"Ew, I forgot to shake the bottle, now there's Pre Ketchup on my chips."
"Don't forget to shake the bottle or you'll get Pre Ketchup."