Yeah, as
@Nurse Ratched said, honesty is key here. I’ve done all of the above. I was a swinger with my ex-husband, and that wasn’t the thing that drove us apart; ultimately it was about his inability to support the family and my drug addiction, which was all-consuming at the time. But the swinger part was fine, and I’ll tell anyone who will listen that it worked for us and I bet he would do the same. We had some good times. Then, right about the time my marriage was breaking apart, I entered into a polygamous relationship with this couple that I know. It only lasted a short time, but it was fairly intense. I learned from that one how difficult it can be to take care of everyone’s needs when there’s more than one other person in the relationship, both in and out of bed. (Like, if they were fighting, whose “side” was I supposed to be on?? And yes, they asked me to take sides, which is part of why it was so volatile. They were a fairly “high-drama” couple, but I stayed friends with them for a while afterwards.)
Point is: adding more people into a relationship is complicated and exhausting, which is why I don’t do it anymore. With swinging, you had to expend so much time and effort locating couples to swing with, and half the time they’d flake on you anyway. With the poly relationship, it’s all the problems of a “regular” relationship, times 2! So I’ve been there and done that, not really interested in a replay. I don’t mind doing a random threesome here and there with my partner, but obviously there has to be a STRONG trust and clear communication, but once you’ve got those two things down it’s really fine…as a spice, not the main course.
But yeah, all of those fears are generally why people don’t practice nonmonogamy. I personally believe that jealousy is a useless emotion that only harms the person experiencing it (doesn’t mean I haven’t felt it; I’m human, after all, but I think I have less of a tendency to it than most.) And I also believe that if, like you said, my relationship is so flimsy that a once-off sexual encounter like a threesome was going to wreck it, better to find out sooner than later. Most times, when that happens, it’s because there was something deeper was wrong in the relationship, not that the other person was just chasing some supposedly better tail…like maybe the other person fulfilled a need that wasn’t being met in the relationship? Idk. But I have friends who are successfully polygamous and they say all the time, you can have some needs met by one partner and others met by another, and you don’t have to LEAVE one to have both. It’s additive, not either/or.
Anyway, I’m too old and tired to have the energy for more than one person except as a very occasional thing, but more power to you if you can make it work