Hi, greenchild, and welcome to the forum.
Let me start this just by saying that I'm not going to judge you as being "horrible" or as sinful or as anything like that. At least, I don't see anything in what you wrote to suggest you are deeply, morally corrupt.
That said, you have messed up, as have the other two involved, and you all seem to have landed in a terrible mess.
There will be pain for some of you, if not for all of you, as you try to extricate yourselves from the mess.
Really, though, the first thing is for you to take responsibility for yourself and your own actions. You'll need to make some hard choices, some of them immediately, and you need to make them for yourself and for your own sake.
Part of what I read in your story is that you and the others have been drifting along, letting things happen, making decisions with judgment impaired by strong feelings or by alcohol.
You need to start making some decisions based on good judgment, guided by your own self-interest, respect for the others involved and for your wider group of friends, and by a good understanding of the situation itself.
I need to be blunt about this but, again, please understand it is not meant to be a final judgment on you. I hope it will be helpful. Here goes:
1. Stop making assumptions.
2. Stop cheating.
3. Stop lying.
The one I love is with my best friend. He claims to be polyamorous and she is monogamous.
He really claims to be polyamorous? What does he understand that to mean? Has he told you, or has he just assumed you'd know what it meant?
Could he be using it as an excuse to fuck around? Do you know that she is monogamous?
This is not to put blame on him - his faults and mistakes are a separate discussion. For the sake of your own decision making, you need to insist on clear answers to these questions. You need to know what you're dealing with.
I've known her for several years. We met him at a party, at the same time, but I was oblivious to whatever advances he made, and meanwhile, they "clicked". Within a few days she was head-over-heels for him, and they were a couple. But I suppose he divulged to her that he had also been interested in me, that he was polyamorous.
In a few days? That seems quick! Do you know what kind of commitment they have to one another? Do you have reason to suppose he divulged any of this to her? Have you asked about it?
Again, you should be more inquisitive, or at least assume less.
And when she told me how wonderful he was, & I expressed excitement & some envy (after she told me how he had been going after me), she all-of-a-sudden threw us together & pretty much said, "Here! She hasn't had sex in a while! Make her happy! I don't care, just don't tell me about it." We were both apprehensive, not sure if this was some kind of test, not sure about each other.
This probably should have set off alarm bells and set the red flags flying. Consider your words: you were apprehensive and unsure . . . but you acted.
That looks to be a big mistake. You should have found out more, forced the conversation, especially
if you have good reason to think she's committed to monogamy. You might just have asked: "What are you up to? What does this mean for you?"
That's all water under the bridge. You might still have to have this conversation, with him and with her. What is
the nature of their relationship? What are
her thoughts on commitment?
And then one night we went to a club, got drunk, & when we were on our way home (with a DD) she suggested that we have a threesome. Both of us were blown away, but she was adamant about it, so... that's what we did. And man, was it weird. And apparently watching him have sex with me really messed with her head. In fact, she was doing all of this to make HIM happy, and & inside she was NOT okay with it, which was an awful thing to do & confusing for both of us. And it's like she held these decisions of hers over our heads from then on.
Again, you seem to be making a lot of assumptions here. You seem to have gone ahead and acted without knowing crucial things about the other two, lulled further into carelessness by alcohol.
Any healthy relationship requires good communication and clarity about consent and intentions. A relationship that would land three people in bed together requires even more communication and clarity.
Again, it's too late to go back and fix this particular set of choices, but these are conversations you still may need to have. You may need to ask her: What did this mean to you? What were you hoping for?
And he was in love with me. And as he has told me, everyone he has connected with emotionally or physically, he still loves, and each person has 100% of his heart. That's why he considers himself polyamorous.
That's nice, and all, but that's not polyamory as it's understood here. His later actions demonstrate that.
(It might help you to read this: http://www.xeromag.com/fvpoly.html
Again, this response isn't about him. But you need to press him on this: What does polyamory really mean to him? Is he aware that people who practice polyamory - as discussed on this forum - are at least
as firmly against cheating as those who insist on monogamy?
If I said that I loved him, I would be confirming it, making it concrete, sealing our fate, & there would be no going back from those words without pain.
There will be pain, no doubt. You can't avoid that now. You may be able to minimize the damage, though, by stopping what you're doing and insisting on total honesty from the guy involved.
Feelings aren't everything. The fact that you're swept up in emotion for this guy does not mean you have
to act on that emotion. In fact, the intensity of the feeling should make you even more cautious about choosing and acting.
(Search the forum for something called NRE. You'll likely gain some perspective from discussions of it.)
And now this has all devolved into full-blown cheating. My friend left for a week, and it got worse. We've been to each others' places. We've had sex a few times. We get together & cuddle, watching movies. It's like we're dating. But he's not "mine". And it kills me to think of how hurt my friend would be. She'll be gone a lot more often, for longer periods of time, at a new job that requires her to drive around the country.
Are you still doing this, or have you stopped due to social pressure? If you've stopped, good. If not, stop now.
Really, just stop.
Then, if you think it's worthwhile to salvage your friendship with him and with her, start talking.
Or, if you just need to keep your distance for a while, then keep your distance, and focus on other activities and other relationships . . . and ask yourself hard questions about how you can avoid drifting in to that kind of mess again.
But now it's all gone to ruin. Our other friends are suspicious. They've been talking about me behind my back. He told me today... and I've never felt so awfully depressed in my life. Gut-wrenching despair.
Really, this is the least of your worries. People will talk, yes. You may get caught, yes. The disapproving gossip of others is not in itself
the reason why some of your choices were wrong.
Whether you get caught or not, whether people gossip or not, the simple truth of the situation remains: you've been assuming, and cheating, and (now) lying, and you need to find the dignity and the strength to stop doing all three of those, immediately, for your own sake
and out of respect for your friend and his girlfriend
As harsh as some of this sounds - and there are others here who will be even more blunt than I've been! - I think this forum may be a safe place for you to figure some of this out.
If nothing else, you can find models here for healthy and happy relationships involving more than two consenting adults, which may help you to understand all the ways in which cheating with your best friend is neither healthy nor likely to make you happy.