A prison officer had a relationship with a sex offender she was supervising and even pretended to be one of his relatives to keep in contact when he was moved to a different jail.
Livvy Edney became involved with Paul Young while working at HMP Channings Wood in Devon.
The 44-year-old used two pay-as-you-go phones, registered a false name and gave an address of one of Young's relatives to prison authorities to keep in contact after he was moved.
She started the secret relationship with Young in November 2022 after becoming his supervisor.
At the time, he was serving an indefinite sentence of imprisonment for public protection after being convicted of assault by penetration.
The prison authorities became suspicious and Young was transferred to another HMP The Verne in January 2023.
However they still stayed in contact and their calls, in which they declared their love for each other, were recorded by prison authorities.
Young also read out poetry he had written for Edney, and they discussed plans for a Venice trip after he was released.
Mother-of-three Edney was arrested at her home in March 2023 and in police interviews denied any relationship with Young, or knowledge of the two mobile phones found at her address.
Young's cell was also searched and letters, notes and a Valentine's card from Edney were discovered.
Read more from Sky News:
Man jailed for religiously aggravated rape
Ex-Channel 5 presenter withdraws claims
The card depicted two penguins and contained a "sexually intimate" message, saying: "Happy Valentine's my love, the first of many.
"Roses are red, violets are blue, I'll make you scream when I put my strap-on inside you.
"Love from your Valentine."
Edney, of Torquay, Devon, pleaded guilty to misconduct in public office at a previous hearing.
At Exeter Crown Court on Friday, she was sentenced to six months in prison.
Judge James Patrick said she was fully aware of the "importance of maintaining boundaries in relation to prisoners".
"Paul Young is somebody who had had a relationship with another officer in the past and that was something which intrigued you," he said.
"From that period, you and he developed a relationship which became closer and closer."
The judge added: "I accept that there's no evidence that there was any physical relationship.
"But plainly, your relationship was highly sexual, even if it was not physical."
Lee Bremridge, defending, urged the court to impose a suspended prison sentence as Edney had since remarried, worked in a full-time job, and was unlikely to reoffend.
"She is not the youngest prison officer, but there is a degree of inexperience in terms of the work that she had performed up to the period of her ill health," he said.
"It really should be set against the background that she is someone who has her own vulnerabilities which started in her childhood, and indeed continued in a 20-year relationship with her ex-husband."
(c) Sky News 2026: Prison officer who had secret relationship with sex offender is jailed for six months
Five charged over rape of teenage girl in Kent
Dan Walker tribunal: Ex-Channel 5 presenter withdraws allegations
Rob Reiner's son opens up on 'living nightmare' after killing of his parents - ahead of his brother's return to court
Man jailed for religiously aggravated rape of Sikh woman
Donald Trump's $1m 'gold card' is yet to pay dividends to US Treasury - with just one approval so far
Trump gives more details about King's state visit
Driver who killed woman in smart motorway crash avoids jail
Man to appeal landmark conviction for killing abused wife who jumped from bridge