"Hetero relationships are based on the idea of procreation and offering a loving environment for your children, therefore by definition would mean monogamy."
Two years ago, the boffin star said marriage was not for him.
"I am passionately in support of it but it's not for me. I couldn't put my Hindu parents through the rigmarole of gay marriage," he said.
According to Sinha, he has always been openly gay, however, Chase viewers only picked up on the fact two years ago.
"They say homosexuality is the love that dare not speak its name, but I've been speaking its name relentlessly now for quite a long time and it seems like only because I've 'come out' on The Chase is anybody actually starting to listen, which I find really weird," he told the Daily Mail.