Jack Nepean sexually assaulted a seven-year-old girl left in his care in Crawley on New Year’s Eve.
An investigation in Devon also revealed how he had also abused a five-year-old girl there.
The victims have been praised for their “extraordinary bravery” in reporting their experience to police.
Nepean, aged 30, was jailed for a total of 12 years when he appeared for sentencing at Hove Crown Court on September 11.
He was told he would have to serve a minimum of two-thirds of the sentence before he could be considered for parole.
The court also imposed an indefinite Sexual Harm Prevention Order to restrict his future access to children and devices.
Sussex Police investigated Nepean, who admitted sexual assault by penetration of a girl under 13 In Crawley, sexual assault by touching of a girl under the age of 13 in Crawley and making indecent images of a child in Sussex.
This took place when the girl was in Nepean’s care on New Year’s Eve from December 31, 2022, into January 1, 2023.
The offences were disclosed to police in early January 2023. Officers from Devon and Cornwall Police identified further offences linked to Nepean’s mobile phone and investigated further sexual offences committed by Nepean.
He admitted to sexual assault committed on a five-year-old girl, making indecent images of the child, three counts of voyeurism, and three counts of possessing indecent images of children in categories A, B and C.
Nepean, formerly of an address in Devon, has now started his prison sentence.
Detective Inspector Iain MacNab from the West Sussex Safeguarding Investigations Unit said: “This was an absolute betrayal of the trust invested in Nepean, who used his position to commit these awful acts.
The child showed extraordinary bravery in telling the police what happened to her. This has had a devastating effect on her and her family however they are receiving support from the appropriate agencies.
“We were determined to get justice for her and ensure a dangerous man has received a significant custodial sentence.”
Detective Constable Pete White and Detective Inspector Becky Davies from the Devon & Cornwall Police Public Protection Unit said: “Nepean committed multiple heinous crimes and I welcome the sentence passed by the judge.
“Our thoughts are with the victims and their families for their commendable bravery and support of the police investigations.
“Their bravery to come forward and speak to police cannot be underestimated and I hope the sentence passed will allow them a small element of closure.”
