An Upper West Side mom was charged with manslaughter over the slaying of her 18-year-old son.

Sean Hines was found dead at about 11 p.m. in the West 92nd Street housing-project unit near Columbus Avenue.

Yvonne Hines, his 52-year-old mom, answered the door to let cops in.

“She had a sponge in her hand,” NYPD Commissioner Ray Kelly said. “It was bloody.”

A neighbor said that the woman “gutted him like a fish” but that as she was being hauled away, she yelled, “My husband did that!”

Hines’ stepfather was questioned over the stabbing, but not charged.