Turner, 20, was standing trial for the second day, facing murder charges against his New Zealander girlfriend Longley.
His parents Leigh and Anita are charged with perverting the course of justice.
Turner’s friend Tom Crowe, 18, told Winchester Crown Court that in the hours before Longley’s death, Turner had taken her phone off her and was reading her texts, and swearing repeatedly.
He also alleges that before entering Turner’s family home on the night of Longley’s death, Turner gave him a hammer and asked him to commit murder.
Crowe said he refused, and before he went home, he saw the couple fight outside Turner’s family home.
Crowe said he heard Longley say to Turner “I hate you”, before she unsuccessfully tried to lock him out of his home.
Crowe told the court: “I felt confused, I felt relieved to get away. I felt scared for Emily – I didn’t know what to do”.
Emily was found strangled in Turner’s bed at the family home in Queenswood Avenue, Queens Park, Bournemouth on May 7 last year.
Crowe said Turner had been “wound up” by Emily talking to other men and said to him: “Oh yeah, she’s pushed me this time. How should I do it Tom, how should I kill Emily?”
Turner had suggested drowning Emily in a bath, setting her on fire with petrol, and a drug overdose, Crowe alleges.
On the first day of the trial yesterday, prosecutor Tim Mousley, QC, painted a picture of Elliot as a “jealous lover” who allegedly strangled Emily in his bed.
Turner told police he and Longley had argued the night before, and she had attacked him. When he woke up beside her she was dead, he said.
By the time police came to arrest him, his bags were packed and his passport was in his pocket.
The court also heard in the weeks after the alleged murder, police bugging tapes in the Turner family home allegedly recorded Leigh and Anita saying they had destroyed a letter their son had written.
Leigh was alleged to have said: “Elliot fucking strangled her”