The distraught parents of a teen cyclist killed by a dump truck said their 14-year-old son went off to play soccer with his friends Saturday — and never came home.

It was only hours later that they learned he had become the 21st cyclist killed in New York City this year.

“You can’t understand this,” Martha Valenzuela, 47, told The Post of Mario Valenzuela before breaking down in tears. “It’s really painful. Not just for me, but the whole family.”

“We are going to miss him so much,” she said. “We know he’s in heaven right now.”

Mario Valenzuela was hit by a private sanitation truck just before 2 p.m. Saturday while riding near a railroad crossing at Borden Avenue and 11th Street in Long Island City, cops said.

His mother said the 8th-grader at IS 216 was a free-spirited kid who loved riding his bike and “liked to feel free, the air go by flying.”

“He was going to play soccer with his friends at the Pepsi sign,” said the teen’s father, also Mario Valenzuela, referring to the landmark inside Gantry Plaza State Park. “He didn’t come back, my wife was looking for him.”

The family said it took them hours before they were able to see the boy’s body on Sunday — doing so only after The Post stepped in to help.

The Valenzuela’s said they had called the Office of Chief Medical Examiner multiple times but had been unable to get any information about their son’s body.

A spokeswoman for the Medical Examiner’s office said the agency has spoken with the family three or four times, but did not comment further.

The 33-year-old private sanitation truck driver remained at the scene Saturday and was not immediately charged, police said.