A paternity test proved that baby-faced 13-year-old Alfie had not fathered baby Maisie with 15-year-old Chantelle Stedman.
Another boy, Tyler Barker, 15, who lives on the same estate as Chantelle in Eastbourne, East Sussex, is the real father.
Tyler told the Daily Mirror he lost his virginity to Chantelle during a one-night stand last May after spending the evening drinking at her home.
He said: “I did not use any contraception, but Chantelle told me she would take the morning-after pill. I thought she would take care of it. Her mother knew I was going to sleep with Chantelle.
“The next morning she even asked ‘Did you have a good night?’ It was routine for boys to stay over with her in her bed.
“But I only slept with her the once. All my mates have been teasing me but it’s not funny.”
If schoolboy Alfie had been the father to three-month-old Maisie, he would have made Chantelle pregnant at the age of 12.
The story renewed calls for better sex education in England, which has the highest rate of teenage pregnancies in western Europe.
The test result can be revealed after East Sussex County Council failed in an attempt to ban reports of the case.
Alfie was told he was not the baby’s father in March, the judgment revealed.
The youngsters were thrust into the global spotlight four days after Chantelle gave birth in February.
Alfie, who lives with his mother Nicola, 43, in Eastbourne, told The Sun – when he believed he was the father ––he “thought it would be good to have a baby”.