Portsmouth Crown Court heard Gerald Hedges, 61, accepts writing the messages under the username ‘Big G’ in ‘Disabled Chat UK’ where the officer told him the fake child had ‘type 21 Down’ with a mental age of five.
But prosecutor Jodie Mittell said Hedges, of Southwood Road, Hayling Island, told police when he was arrested that ‘it was just a bit of a joke’ and ‘he was winding someone up’.
Opening the case against Hedges, Ms Mittell told the jury: ‘He’s asked “when can I come over to move in as a lodger... to share both girls”.’
When the officer, posing on the chatroom, asked: ‘Move in as a lodger?’ Hedges replied: ‘And kid’s lover,’ the court heard. In one conversation Hedges said: ‘My bag is packed.’
The defendant denies a charge of attempting to arrange the commission of a child sex offence.
Jurors heard the undercover officer told Hedges he had a baby. Ms Mittell said: ‘Mr Hedges is not only interested in knowing about the eight-year-old, asking “will you keep the baby?”’
In another message Hedges said: ‘Yes, I’ll stay with you, help with the costs and (have sex with) daughters.’
After officers arrested the defendant over the messages, which were sent in May and June 2017, their investigation heard from two women who separately alleged Hedges raped them around 30 years ago.
Two other women told police they were sexually abused as children, the court heard.
Hedges denies seven charges of indecent assault, another child sex offence, and five rape charges.
The court heard one complainant told police Hedges said: ‘I’ll have to go to prison if you tell anyone.’
Separately jurors heard Hedges was known to be ‘particularly interested in young girls in school uniform because he would slow down in the car if they were walking past and would make it fairly obvious that he liked young girls,’ the prosecutor said.
The court heard Hedges told police he had consensual sex with the adults, and that the child abuse did not happen.