The man accused of murdering New Zealand student Emily Longley told a jury he didn't realise she was dead because he was "not a paramedic".
Elliot Turner, 20, allegedly strangled Emily, 17, at his parents' home in Bournemouth, Dorset.
She was found dead in his bed on the morning of May 7 last year.
Continuing his evidence in Winchester Crown Court for the third day yesterday, he said he thought "something was wrong" when he touched her cold cheek at about 8.45 in the morning.
But it was another hour before paramedics were called.
Asked by prosecutor Timothy Mousley, QC, why there had been a delay Turner said he hadn't realised she was dead.
Mr Mousley: "It would be obvious to anyone that she was dead."
Turner: "No. I'm not a paramedic. I've never even seen a person unconscious. I've never done any first aid.
"She was cold. I woke mum up, she came and shook Emily and tried to wake her up."
Pressed by Mr Mousley, he added: "So many times before I have tried to wake her up and she does not get up."
Mr QC Mousley asked Turner if Emily had simply passed away mysteriously in the night.
He said: "Yes, well, I don't know. I'm not a psychic."
TURNER CHALLENGED ON POLICE RECORDINGS
Turner was also asked about police recordings taken from his house in which he is heard asking his mother to change her evidence.
Asked why, he said his mother's initial account had seemed "weird".
Turner said: "I wanted my mother to change her account to police because she had said that she had called an ambulance first, but in fact she'd called my father first.
"I thought that would look bad."
Turner admitted he had been controlling and threatening towards Emily at times during their relationship but said he did love her.
Asked if he was any way responsible for her death he replied: "No, I don't believe so."
Earlier, Turner said he and Emily fought in his room on the night she died after she threw two drinks over him earlier in the evening at a bar.
Emily had punched him in the face, and after he responded by pushing his right forearm into her neck, she kicked him in the face and stomach.
Mr Mousley asked Turner why he had not shown any remorse over Emily's death in court.
Turner said: "It's just been a completely weird situation. Just a nightmare.
"Obviously I have been sad about about my girlfriend. This was a year ago."
He added: "Obviously I've been sad but I've had to contain myself. I've got to answer questions and I can't break down."
Turner was asked what words of sadness he had expressed about Emily's death.
He said: "I said to my mum that I couldn't believe she was gone, that I wanted to marry that girl and I couldn't believe she was not in my life.
"Every single one of my friends will tell you that I did not stop talking about her, how upset I was about the situation."
Turner was also asked whether he was trying to make people think he was capable of serious violence.
He told the court: "I am not capable of serious violence. I do play pranks to show off."
Talking about an incident when he took a lump hammer into Klute nightclub, he admitted he had been 'stupid'.
He explained: "I did it to show off. It was stupid at the time, I just wanted to impress them."
He also admitted to the court that friends didn't take him seriously.
He said: "Every single person would say that I talk so much s***.
"I'm always laughing and joking all the time. That is my type of personality. Always friendly, always having a laugh."
He also said that Emily had not taken his threats to kill her seriously.
He said: "She did take it as a joke, I did not literally mean it."
But later, when he was reminded of a letter she had sent him in which she had said 'please don't say you will kill me' he said 'maybe she didn't think I was joking.'
The court also heard Turner had become angry after seeing pictures of Emily with The Cheeky Bus Butlers, a group of men who serve drinks at parties.
He said he was upset the aspiring model had done the photoshoot posing with scantily-dressed men.
Turner added: "I was upset and surprised and annoyed.'
The trial continues tomorrow.