A man was arrested after grabbing a child’s butt while she was inside a Brooklyn grocery store, police said.

Roman Gomez, 36, allegedly grabbed the 12-year-old’s buttocks around 1 p.m. Wednesday inside 4406 Fifth Ave. in Sunset Park, cops said.

He was immediately arrested and charged with sex abuse, forcible touching, harassment and acting in a manner injurious to a child, court records show.

Gomez has an active warrant for his arrest in Manhattan, police said. He was arrested at least twice before for public lewdness in 2012 and 2016, police sources said.