A MUM-OF-THREE who boasted about how long a teenage boy she was fostering could last in bed has been jailed for more than three years.

The woman, who cannot be named for legal reasons, told friends she shopped at Ann Summers and had regular sex with the boy she had fostered for five years.

She told a friend she had been having sex with a mystery man half her age and gushed about how long he could go and last.

Lewes Crown Court in Hove heard they had sex on at least six different occasions in the family home when he was aged 16.

Sarah Ellis for the Crown told the court despite agreeing not to tell anybody about their relationship, the woman told friends and showed them text messages.

Ms Ellis said the woman told police she was not looking for a relationship with the boy and did not realise it was an offence to have sex with her foster son.

"She was not going after a relationship, just sex," Ms Ellis said.

"She denied buying condoms and lubricant but admitted she did go to Ann Summers."

The foster mum regretted her mistake, Ms Ellis said.

In her statement, the woman admitted she would consider getting back with the boy in a few years, the court heard.

"She said it was just one of those things that happened," Ms Ellis said.

The woman fostered the boy for a number of years before the abuse started.

A judge told the 36-year-old from Brighton she was guilty of a colossal breach of trust by having sex with a boy she was fostering.

His Honour Judge Stephen Mooney said she was taking the place of his mother.

"When he was at his most vulnerable after the death of his grandmother, you embarked on sexual relationship with him.

"You betrayed the trust he had in you.

"It was a colossal breach of trust."

The woman was sentenced to 40 months in prison and told she would serve half before being released on licence.

She will be a registered sex offender and the court issued a Sexual Harm Prevention Order.

She is also banned from fostering any more children.