Birmingham Crown Court heard that Coe, whom it is believed changed his name to Seb from Barry, sent thousands of texts to under-age girls as well as many to their mothers.

His 14-year-old victim told the court Coe’s texts became flirty before he sent her an obscene photo of himself. The former firefighter told the underage girl he fantasised about having sex with her and pop star Rihanna.

When the 14-year-old told the police about Coe’s behaviour, a subsequent investigation revealed he had sent inappropriate and explicit texts to two other young girls.

Originally from Sutton Coldfield, he was sacked by the West Midlands Fire Service for downloading pornography on a work computer.

He is due to be sentenced on Friday 13th June.