"It all started when we decided to have a threesome."
Background
I have always been a monogamous person. So much that when another person would so much as look at a partner, I would stink eye them into oblivion. My relationship that I'm in now is perfect, but there was something missing when it began. It had nothing to do with her, and everything to do with what I was realizing about myself. Don't get me wrong, I love my girlfriend and she is perfect for me in every way. The sex is mutually amazing, and we truly care for each other in a way that I have not experienced with other partners. Now, that being said, I thought long and hard on what it would be like to bring another person into the bedroom. I figured that was the issue because we almost broke up over me wanting to stray. She had already been in non-monogamous relationships, but I was a newbie even to the idea. After I was comfortable with the idea I brought it up with her. Her response was better than I expected, and really made our relationship grow in a fantastic direction.
"Sure!" She said. "How do you want to go about finding someone?" The question kind of flabbergasted me. I didn't even think of that. All I thought about was our comfort. I suggested using OKCupid and she thought it was a good idea. We set up a profile, took some pictures, and looked around for a bit. Pretty much the first person we looked at turned out to be the perfect match. We sent her a message, and we decided to get together for coffee later in the week.
Meeting
When we saw her at the coffeehouse, she was prettier than in the pictures. She was also extremely nice and believed in most the things that make up the fiber of my being. I am not going to go into too much detail here, but we decided go over to her house on another day to have our fun.
Here is where I'm going with this: IT WAS AMAZING. It worked out well for all of us. My partner hasn't really been with too many other women, and neither have I (sexually). We got to meet her husband after (yes, she's married and they are polyamorous) and we went out to a great dinner. It was fun! We still go hang out with them all the time, and we don't just meet up for sex. We like to think of them as friends that we happen to have sex with. To think, it all started when we decided to have a threesome. I never even considered the idea, and it turned out that it was what I was missing.
Polysexuality
The reason our relationship differs from that of a polyamorous is the love and relationship aspect. My girlfriend is the only girl for me (romantically and emotionally). With that in mind, there is no denying the physical attraction to other people. Therefore, we are romantically monogamous and sexually poly. It's a fine balance but it really works for us. That's the beauty of relationships, they are all different dynamics and don't work for everyone. There are some people that can't do it because of jealousy, and some people can't do it because of their own body image hang-ups. There are some that it works for, and some that just want to try it out.
When it comes to your relationship, it's all about a few key elements:
Communication: Communicating with your partner and being honest about your wants and needs is the most important element.
Consent/Boundaries: As long as there are boundaries set to make sure that everyone is comfortable, things should go well. However, sometimes it's different when the idea becomes a reality. Be honest with yourself, and be honest with your partner(s). Never do anything that was not agreed upon beforehand.
Trust: If you are meeting new people, safe sex is the way to go. Always wear a condom until everyone can prove that they are STI/STD free. Once you feel like you can trust these new partners, and all is consensual, then you can stop using condoms (provided all females are on some sort of birth control).
Polysexuality is what really works for me and my partner. If you think it would work for you, then that's great! If not, then don't knock it. Find what works for you and your partner(s) and roll with it.