A grieving grandmother railed against the “cruel monster” who slaughtered her daughter and two grandkids in a Brooklyn bloodbath, as a judge sentenced the killer to 40 years to life in prison.

Ana Ybe tearfully denounced Jermaine Ruiz for killing Jessica Ybe and two of her daughters from other men — Jelyhanna, 2, and Sasha, 3 — in a fit of jealous rage, while sparing the 10-month-old twins he’d fathered with her.

“You are not a human being, you are a cruel monster,” said Ana Ybe. “I hope you never get out so you won’t kill any more children.”

Ruiz stabbed the victims inside Jessica Ybe’s East Flatbush apartment in 2010.