A married man killed his lover, hid her body and kept up a charade that she was still alive for 18 years, the Old Bailey has heard.
Kevin Doherty even made two sham calls to himself claiming they were from Jane Harrison, 32.
He told police he thought she had gone off with another man, jurors were told.
Jane Harrison, who has been missing since 1995
She was last seen shopping with him for a holiday they were due to take two days later in June 1995.
But the prosecution said he killed her, took her body to a lock-up garage and reported her missing the next day.
The body of the mother of two boys has never been found and the evidence against Doherty was only circumstantial, said Jonathan Rees QC, prosecuting.
Doherty, 57, of South Woodford, east London, denies murder.
Rees said a few hours after she disappeared, Doherty used his mobile to secretly ring Miss Harrison's flat in Highbury, north London.
He picked up the phone and was heard to say: "Where are you now?"
The babysitters said Doherty looked "sweaty and panicky" and claimed it was Miss Harrison on the phone, saying she would be home later.
Rees added: "This purported phone call was nothing more than a continuation of the charade the defendant had embarked upon.
"This call was not made by Jane Harrison. The call came from his mobile. He was pretending to speak to Jane."
Shortly afterwards, the phone rang again when Miss Harrison's teenage son Ryan returned home and asked where his mother was.
He heard Doherty say: "Don't worry, come home."
Mr Rees said: "This was the second sham telephone the defendant made to the flat using his mobile phone, pretending to be Jane Harrison. Essentially, he was trying to manufacture an alibi."
Doherty was questioned about her abduction in 1995 but was arrested last year after a murder inquiry was launched.
He told officers they had an on-off relationship during the three years they were together, with him sometimes living with his wife.
Mr Rees added: "He said he did not kill Jane Harrison and they had not argued.
"He said he was not a jealous person even though they had split up on a number of occasions.
"He said he kept going back and was besotted with her. It was a sexual thing and he was not in love with her."
Mr Rees said Miss Harrison was last seen at Wood Green Shopping City, north London.
Doherty claims to have dropped her off near her mother's house in Stoke Newington before going to her flat nearby.
Extensive records checks failed to establish she was still alive although the body had not been found, said Mr Rees.
She was a devoted mother to Ryan and Taylor, the baby she had with Doherty. It would be inconceivable that she would not contact them if she was still alive, he added.
Mr Rees said Doherty, who had three children from his marriage, was working as a warehouse manager at the time and often hired vans.
Miss Harrison liked going on holidays and he would pay for her and her family to travel to countries such as Portugal.
"The defendant and Miss Harrison maintained that volatile on-off relationship until her disappearance," he added.
The trial was adjourned to tomorrow.