Shrien Dewani told his wife Anni their marriage was "not natural" in emails exchanged soon after their wedding.
Dewani, who is accused of her murder, poured his heart out in emails which shocked and alarmed his wife.
Anni was shot dead during the couple's honeymoon in Cape Town in 2010, weeks after reading the emails.
She threatened to leave him for good after the troubling emails revealed he was "forcing" himself to be with her".
"Just because we had a bollywood wedding doesn't mean we r bollywood actors and just pretending that everything is good when it isn't will just end up with us hating each other," she wrote in her third language.
"Seriously, do you want me to leave you? Its very mean of you to tell me these things that you told me just after marriage then you should have told me this before!!!
"I don't want an insecure man or a man that feelings doesn't (sic) come natural that you have to force yourself.
"Never expected things like that from you. Never expected things like that from you but now I want you to tell me exactly how u feel and honestly, u hurt me a lot by this and I am ready to pack and leave and this is not a joke! I can't even sleep at night.'
Replying, Dewani said: "When I said it was not natural and was forcing myself – we were talking about not feeling happy. Not that I was forcing myself to be with you."
Dewani admitted earlier at his murder trial that he was bi-sexual and had secret encounters with a bondage prostitute called the German Master.
Police recovered the emails from Dewani's phone a month after Anni was killed.
Dewani claims they were victims of a car-jacking while in a taxi. Prosecutors claim he set up his wife's killing to make it look life a botched robbery.
The trial continues.