SNOHOMISH -- When a 14-year-old Snohomish boy arrived home Thursday after D's and F's appeared on his report card, a man allegedly spanked him with a stick so hard the boy's buttocks bled.

The man was the boy's mother's boyfriend, Snohomish County sheriff's spokeswoman Rebecca Hover said.

The boyfriend, 41, told police "the spanking was harsh," that he'd like to "replay this day" and said he regretted hitting the child.

Police were called around 5:30 p.m. Thursday to a home where a neighbor had taken the boy after the spanking, according to a police affidavit filed Friday in Everett District Court.

The boy's buttocks were bloodied and bruised. He had six red marks across his back and he told deputies he thought his left arm was broken, the documents said.

Paramedics rushed the teen to the hospital when his blood pressure began falling rapidly.

Deputies interviewed the boyfriend, who allegedly admitted taking the boy to a garage and hitting him with a wooden stick. The man said the boy was late coming home and had failing grades on his school report card. Police found the stick broken into three pieces, the documents said.

The boyfriend told police, "I would never draw blood on a child." When police told the boyfriend the extent of the boy's injuries, the man covered his face and muttered, "Oh God," the documents said.

The teenager also told deputies the man allegedly choked him so hard it was difficult to breathe.

The man was booked into the Snohomish County Jail for investigation of second-degree domestic violence assault. A judge Friday ordered him held on $100,000 bail.

Reporter Jackson Holtz: 425-339-3437 or jholtz@heraldnet.com.