Seriously, we need to wipe the word "naturally" from our human behavior vocabulary. It serves no actual function and leads to a lot of asinine conjecture. Because too often we conflate "natural" to mean "normal" and "right" and "easy." And when it comes to human behavior, I'm pretty sure none of those words are useful.
Take Scarlet Johansson's latest comments on marriage: "I don't think it's natural to be a monogamous person. I might be skewered for that, but I think it's work. It's a lot of work." Really, Johansson?!
Look, I've gone through long periods of celibacy, I've been in casual relationships, monogamous relationships, and poly relationships; let me tell you: It all takes work. Life, if you're trying to do it ethically, takes a lot of work.
When I was celibate, I constantly had to field questions about why I was celibate and when I was going to "get back out there" because "the clock's a-ticking and you don't want to end up alone." I constantly had to defend my decision to focus on other areas of my life other than my romantic status and insist that there was nothing wrong and that I wasn't broken or damaged or lonely. It felt like I was constantly trying to explain that being celibate isn't the same as being alone and being alone isn't necessarily the same as being lonely.
When I was in casual relationships, I had to deal with people telling me to settle down or make a decision. "Is this the person the lucky one who's going to last or not?" I also had to deal with the judgment of being called a slut or too picky, if turns out they weren't. Not to mention, well, having to just make a lot of day-to-day decisions. Do I go out tonight? Do I stay in? Do I really want to go out and make the effort to find a partner? Not to mention having to size-up every new partner and make judgments on whether or not they were someone I wanted to take a chance on or not, for my own self-protection as well as theirs. Not to mention if I wasn't interested in a long-term relationship, I constantly had to lay down and maintain boundaries, because, as much as no one wants to waste their time on partners who aren't interested in your well-being or who aren't interested in the same things you are, I'd hope no one wants to be one partners feel they've wasted their time on either.
When I was in monogamous relationships, a lot of that day-to-day stuff is easier. Typically, you know who you're going to have dinner with or who's house you're going to sleep over at. You don't worry so much over whether you'll regret going home with that person because of their temperament or safety status. People tend to bug you less about about your perceived promiscuity or likelihood of dying alone. But they do start pestering you about your future together with invasive questions about marriage dates and baby announcements. Not to mention, now every time you try to schedule anything, you have another person to consider. It's never what I want for dinner, it's what WE want. Before I can agree to any event, I need to make sure we don't have plans already. Every life plan you make, from what you do, where you do it, how long you do it, who you do it with, has to take another person into account.
When I was in poly relationships, it just meant multiplying those exact same issues. Instead of taking another person into account, now I was taking a lot of people into account. In order to make that kind of relationship work, you're constantly talking and checking in with everybody to make sure that everyone is feeling properly accounted for and no one feels left out or neglected. You're juggling not just one person's schedule and feelings and input, but multiple. Not to mention that most of the time you're pretty in the closet about it, since society is still pretty uptight about that. So some people in your life know about it, some people don't, and it's a constant balancing act of trying to explain your life to a bunch of people who have differing levels of information clearance. And you constantly have to worry about who knows what because, if the wrong person finds out, it could mean the loss of someone's job or kids or social circle. Added into that, even with the people who do know, you're often fielding awkward questions about who does what with whom and whether you have a problem with it.
Don't get me wrong; each relationship I've ever been in has corresponded to a moment in my life and a stage of my growth that fit at the time. It was a combination of the people I was involved with and the circumstances I was dealing with in my life at the time. Each relationship was filled with incredible benefits as well as inevitable drawbacks.
Because that's how life works.
Nothing worth having comes to you without work. Nothing worth having is kept without work. And, maybe it's because I'm kinda a socially awkward introvert with what pop psychology labels attachment issues and a tendency to overthink, I'm fairly sure that nothing involving another person is ever easy and requires no work. We are complex creatures; how could combining complexities ever be easy?
We all just do the best we can with what we have.
Find relationships that work for you. That feel "natural" or "normal" or "right" for you, whatever that means in the moment. And understand that, while I hope that you are able to find and enjoy that, your natural, your normal, your right has absolutely nothing to do with anyone else's. If you are not in a relationship with someone, what they decide to do, however they decide to do it, and with whomever they decided to do it with, none of it is your business.
Don't judge others.
Don't prescribe to others.
Don't project yourself onto others.
So long as no one is being harmed, just you do you and let everyone do the same.