Kieran Binns groomed one of his two victims through social networking site Bebo before seducing her at his flat when she was just 15.
Yesterday, the girl's mother told of her horror at discovering 22-year-old Binns had "stolen her innocence" after inviting her to watch DVDs in his home.
The mum, who can't be identified for legal reasons, said: "She was a virgin when she met Binns. He started staring at her in class and sending messages.
"It was all on Bebo and the police took the memory stick with the messages he sent on it.
"When he asked to meet her, she thought they were going to watch DVDs at his flat. She said she felt stupid and that's why she went along with it.
"At one point, he asked her if she would run away with him."
But after the pair slept together, he turned on the girl.
The mum said: "My daughter told me that after they had sex, he started calling her names and was very insulting. She felt it was all her fault."
Police were called when the second girl's mother intercepted texts from Binns to her daughter's phone and she revealed all when questioned.