I have first to point out that all of us come from one culture or another, or from many cultures.
And yet all of us are
equally free to accept, reject, adapt, subvert, embrace, or selectively endorse the values which those cultures can only suggest to us.
So stop worrying about "your culture." It isn't yours or anybody's. No culture is "yours." Moreover, no culture is "not yours." When you decide what you will accept in a relationship, you're really talking about your values. They are truly yours. Your happiness can be based on any idea from the common heritage of mankind.
And though I have no south Asian heritage, I shared the same values of waiting until one person would be confirmed as my one partner in life. Loyalty and a lifelong journey were more important to me than the idea of sex.
That principle sustained me but also allowed me to hide from my true sexuality. When you decide to wait for marriage, you can date a woman for a really long time without any questions being asked about sexual orientation because after all, you're waiting for marriage. I almost made a terrible choice.
When I came out, I discovered that recognition of my desires did not change my values and the importance I place on loyalty.
I met some people who thought of that as perhaps a romantic ideal, but impractical. Other people who were horrified by the idea and thought I was limiting myself somehow by not having random sex with people soon to be forgotten. And the very few people who might have shared the same approach to relationships were no closer to being a good match for me just by virtue of sharing the same values.
Faced with this unfulfilling situation, and going on a few years of celibate dates with different men whose values I quickly learned were quite divergent from mine, I let myself attempt something less than a real relationship with someone who had been a longstanding friend. But I couldn't go through with it! I called things off partway through an intimate situation that was intimate only in the physical sense of proximity, and even then we didn't really get anywhere...
There was no choice for me but to wait. As frustrating as that was, it would just have been foolish for me to continue denying what I need for a physical sexual relationship, which is love, loyalty, partnership, a future, and a shared life.
And, in my mid twenties, I found the man I'm with 13 years later. He too had very limited prior experience, and most of our sexual knowledge is only of each other. We have a full relationship in all respects, and though marriage was not legal in Canada when we first met, it would have been our path at the time if it had been an option.
I couldn't have the kind of relationship you want for the reasons you want. I could not accept a physical relationship that was based on any concept of dominance or submission. I don't understand how that relates to the physical act of making love, even less so in a homosexual situation than a heterosexual situation; my mind just rejects it, cruelly if need be. The idea of a non-versatile relationship, barring some kind of medical justification, actually provokes a physical reaction of distaste.
But to each his own!

And the concept of exploring sexuality within a framework of loyalty is completely familiar to me, and from my own experience, it is better to just wait for it rather than try to force yourself into something else. Trying to force myself into something else and bailing before it really got anywhere, it just became apparent to me how futile that would be, and wasted the time of someone with different ideas of how to spend a fun evening.