Snooki's ex-boyfriend Emilio Masella doesn't think the world is ready for Snooki spawn ... including Snooki herself -- telling TMZ, "I hope for her sake ... not to be rude or anything ... but I hope she has a miscarriage."

Emilio tells us he does believe Snooki will eventually be a good mother -- but insists ... there's no way in fist-pumping hell she's ready for it now.

According to Emilio, Snooki has always been flippant about having kids ... and never really grasped the gravity of being pregnant -- "When I was with her, she said she wanted twins. She would always say 'Let’s have twins.'"

Emilio says, "I would def recommend her to get a paternity test to see who the father is because I’m sure there are other subjects" -- adding, "Vinny could easily be the father."

As for how Snooki and BF Jionni's relationship will pan out on her new spin-off show -- Emilio thinks the two will get married ... but Snook will "pull a Kim Kardashian."

Emilio says, Snooks is "going to have the baby and break up with him right after."