How do I explain to others that it's not their concern if I choose not to have sex?

I think you could just tell them, that for your personal reasons you don't want to. If you are comfortable with doing so, you could explain why as most people would give it up once they understand why. However there will always be a few people who cannot understand, in those cases you could just make it clear in a friendly but firm manner that you don't want to talk about it, and to please not bring it up again :) I hope this helps!

I think, That what you do should be none of anyones business. Tell them ,straight that you don't appreciate them poking their nose in your personal life. Having or not having sex is a personal preference and should not be dependent on anyone but You alone.

Tell the people that are troubling you that everyone is different and this is how i choose to live my life.

Telling them straight forwardly is the best option. Sometimes u have to be straight to some people so that they get it into their heads.

You should not have to explain yourself at all to others. If they do not respect when you say that you're choosing not to have sex, then they are probably not the best people to hang around. You need supportive people in your life that will not question your reasoning behind personal choices. Make sure you stand your ground--it is your body after all!

Since you're in college, you could try explaining it to them like choosing a college major: it's not anyone else's concern/right to choose it for you. Instead it's entirely your own choice to make and should reflect what you feel is best/most satisfying/most comfortable to you. If they have opinions about your choice, that does not mean that they get to influence it or get to make you choose how they choose or how they want you to choose, so they're much better off just sticking to their own decisions and worrying about their own sex lives instead of yours.

Sex is a personal bond between two consenting people. It should not be the business of anyone else under normal conditions.

The vast majority of human beings are sexual. We're physiologically wired to enjoy sexual contact. Stimulating dangly bits, or giving attention to internal bits... our species literally lives or dies based on how frequently we do that. Masturbation takes advantage of that drive and gives personal pleasure, but *some* form of sexuality is something that many people feel is an intrinsic part of humanity. "I don't want to have sex" comes across to most people as weird, and triggers curiosity because it's an outlier. "I don't want to have sex tonight" and "I don't want to have sex with you" are more understandable to a species that requires sex for survival. "I don't want to have sex, ever" is hard to make sense of. But in the end, I agree with coffeeprincess. You've explained it perfectly, and it's totally valid for you to set your own boundaries however you want. If you want others to understand, however, I think you'll have to do more than explain it well.