Medouni said he suggested burying Miss Lionnet in the garden, but Kouider wanted to disguise a pyre behind a gazebo.
The defendant said Kouider ordered him to buy the tent from B&Q but he did not.
Meanwhile, she took a shower saying it was to clean her sin, jurors heard.
On September 20 last year, Kouider took Miss Lionnets body outside in the suitcase and they burned it near the house, the court heard.
Medouni said they cooked chicken on a barbecue nearby because of the smell.
When firefighters uncovered the charred remains, Medouni claimed it was the carcass of a sheep, which he told jurors was stupid.
He said he explained what happened because he wanted to protect the family and myself.
Orlando Pownall QC, defending, said: Mr Medouni, you have said a number of harsh things about Ms Kouider.
What are your present feelings for her?
Medouni replied: She destroyed my life. I have my part as well. I could have stopped her. I could have done things and Sophie would have been alive.
So I hate myself for that, for letting the violence grow without calling the police or go to emergency services because I had many occasions to do that.
Mr Pownall recalled an incident in court earlier this week when Kouider called Medouni a murderer from the dock.
Medouni denied the accusation, adding: I never, ever, ever slapped, beat a woman. Im not violent.
The couple have admitted perverting the course of justice but deny murder.
Cross examining, Icah Peart QC accused Medouni of telling lie after lie about Sabrina and what happened at their Wimbledon Park Road home.
Kouiders lawyer pointed out he could not even look at the woman in the dock he professed to love.
Medouni replied: No, I think she is lying to you.
He described himself as a follower, a bit naive and too nice but denied being self centred.
He said: I dont want to pay for something I didnt do. Im not an egoist.
http://home.bt.com/news/uk-news/murder-accused-cried-what-have-i-done-court-told-11364265127573