David Wilkinson posed as a GP to convince a 13-year-old girl to meet him after an online sex chat in 2019.
But when he turned up to meet the child, who did not exist, he was confronted by Dark Justice, who filmed him as he tried to run away – and fell over twice.
Wilkinson, who did work for the health service but was not a doctor, was jailed for 16 months and given ten years on the sex offenders’ register, with a sexual harm prevention order.
At Newcastle Crown Court the 43-year-old, who is now assessed as a "very high risk to children" was jailed again for having sex chat with an undercover police officer who he thought was a 13-year-old girl.
Prosecutor Alec Burns told the court Wilkinson, who was also jailed twice in 2020 for similar offending, had been released from prison in May last year.
In September, while still on licence, he started chatting to a teen online profile.
Mr Burns told the court: "He was communicating with what he thought was a 13-year-old girl but was in fact an undercover officer.
"He was told in the initial conversation she was 13."
Mr Burns said the conversation had moved from the chat site to WhatsApp and Wilkinson said the girl was "sexy".
When asked what he was looking for, Wilkinson boasted: "Haha, young girls like you."
Mr Burns added: "He said he was a naughty man who likes young girls and very quickly suggested meeting up."
Wilkinson said he would buy the teen pink gin, said he loved her and that they could have sex at his house.
The court heard two meetings were arranged, but neither went ahead.
He used a false name during the conversations and when his house was searched, police found a mobile phone which was internet enabled and should have been declared to the authorities to comply with his sexual harm prevention order.
Wilkinson, of Jubilee Road, Blyth, admitted attempting to have sexual communication with a child, two charges of attempting to meet a child following sexual grooming, breach of a sexual harm prevention order and two charges of failure to comply with notification requirements.
Judge Edward Bindloss sentenced him to three years and nine months behind bars, with an extended five-year licence period.
The judge said Wilkinson was a "dangerous" offender who is a "very high risk to children."
The court heard Wilkinson has an isolated lifestyle, with no partner or children.
Nigel Hedley, mitigating, said Wilkinson had "more victim empathy than before".