What does Dubai (a city) have to do with India (a country)? Plus, you're comparing homosexual to heterosexual relations.
Having lived in Dubai, I know of plenty of people who had sexual relationships without being married (not that I approve of that), and they were never arrested. The only cases I have heard of where arrests did happen were in cases where they happened in public.
Actually Dubai is worse, if you are caught having sex with your girlfriend you can get jail time because you're not married.