What do I do?

I'm a 28y M earning well in a reputed internet company. I come from a very conservative family and am the youngest of three, my elder brother and sister being married and having kids of their own. My parents are pressuring me to get married for a while now and the push is only going to increase. I haven't been in any serious or even casual relationship all my life, the main reason being that I am gay or at the very least bisexual and the thought of being in an arranged marriage(do look it up to understand how it works) scares me. That being said, I certainly don't see myself in a same-sex relationship/marriage either. While I do want to have a family of my own some day, I don't know if I'll be rid of the urge to indulge in fornication with the same sex. Will that constitute cheating, IF it happens? Coming out to my parents and family is not really an option and will hardly accomplish anything anyway. I've read countless articles about what constitutes a good marriage, and seen many examples around me to make me think. While impassioned sex is not the only basis for a good marriage, I am well aware of the human tendency to take what you've got good for granted and focus on the supposed shortcomings. We do this in every sphere of life. I fear this could be the case with my spouse too, eventually. What do I do? My time is running out to take a decision.