Colin Lowrie was still on licence from his last jail term when he started chatting to a 13-year-old girl over dating site Tagged and said, during a series of shocking online conversations, that he wanted to have sex with her.
Newcastle Crown Court heard the 25-year-old repeatedly told the profile, which was actually being run by a police officer as part of a covert operation, belonged to a child, but he continued making explicit chat.
Lowrie, who was once in court for having sex with a woman in the North Marine Park in South Shields while a family treasure hunt was going on, has previous convictions for sexual assault on a 13-year-old.
He also breached a sexual harm prevention order by befriending another 13-year-old girl online, and was jailed in 2017 for inciting a 15-year-old girl to exchange illicit photographs with him.
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Judge Robert Adams sentenced him to 20 months behind bars, with a 10-year sexual harm prevention order and 10 years on the sex offenders' register.
The judge told him: "You were caught out by an undercover police officer sting operation on a fake profile.
"The profile and the photograph contained information that the child concerned was a female aged 13."
The court heard Lowrie has been assessed as posing a "high risk of sexual re-offending" and a "high risk of serious harm to children".
Judge Adams told him: "It seems to me you clearly do pose a significant risk of serious harm, particularly to children, as a result of your continued offending."
Lowrie, of Commercial Road, South Shields, admitted attempting to engage in sexual communication with a child and acting in breach of a sexual harm prevention order.
The court heard the message exchanges took place in January this year after police set up the fake online profile.
Prosecutor Kevin Wardlaw told the court: "He asked her if she had a boyfriend. On being informed she didn't he suggested he could be her boyfriend.
"The profile said her mother would be unhappy and he said 'don't tell her, we can keep it a secret'."
Mr Wardlaw said the exchange "became sexual" and Lowrie asked if she thought he "looked hot", said he had been dreaming about them being in bed together and discussed how he would avoid her getting pregnant.
Lowrie had told the girl "love you baby" and considered, in early conversations, waiting until she was 16 as he didn't want to "get done for sex with a minor".
Vic Laffey, defending, said Lowrie has limited intellectual function and complex mental health problems.
Mr Laffey said Lowrie had stopped taking his prescription medication and was using alcohol at the time of the offences.
Mr Laffey added: "He struggles to maintain age-appropriate relationships."