Do I Need to Be Friends with My Metamours?
TL;DR: Never force a relationship with a metamour. Here are examples from my first two years in non-monogamy.
Meta #1 (2012-2013):
My first meta and I lived over a thousand miles apart from one another and we tried hard to establish a friendship over the phone. We tried to find common interests, but to be honest, I really don't remember much of what we tried to connect over. It was awkward, to say the least, but we figured that was part of the deal and we'd eventually get through it.
Our partner at the time was the untethered wanderer type -- good god, never again -- so he would spend a couple months at a time with her in Arizona and then with me in Portland. Meta and I were in school so when an academic break arrived, we made the effort to all be in the same place. All in all, we got along amicably. We were both fairly respectful and took measured care not to cross one another's boundaries.
Meta #2 (2013-2014):
My second meta and I lived in the same city. I met her almost immediately after she and our partner started dating, a few weeks after meta #1 broke up with him.
While this meta and I had respective alone time with our partner, we spent time together as a triad more often than not, trying to create a "poly family."
The other meta-ship had the long-distance advantage so we could not force one another to physically be in the same space all the time, even if we wanted to. However, because distance was not an issue this time, I felt even more pressure. I feared that if I failed to be a "good meta," it meant I was just "the jealous girlfriend who was actually monogamous all along."
Because I was too preoccupied in my own worries, it took me a while to see that this meta had actually been playing at non-monogamy and ultimately wanted to be monogamous with our partner all along.
In both relationships, I ended up not acknowledging that I had boundaries and needs. I spent far more time around my partner and meta than I wanted.
I felt I had to listen whenever my partner wanted to talk about the explicit, intimate details of his other relationship. I did not feel I had the right to stand up for myself when I was in sexual threesomes that I was not comfortable with and that made me feel terrible afterward.
In classic codependent fashion, I dishonored myself by tying too much of my worth into what my partner and my metas thought.
You don't have to be best friends with your metamours. You don't even need to get to know one another at all if that's not your style. As with any relationship, it's up to you how much you decide to invest.
Kitchen Table Polyamory is rad when it happens. I appreciate being able to meet metas and develop familiarity and cultivate sense of ease together, but it is by no means a requirement. If I do get to meet my metas, as with new friends or potential partners, I have no expectations for what that relationship will be. If we connect and become friendly, awesome. If we merely acknowledge one another with a head nod every once in a blue moon as we drop our partners off, also awesome. Whatever works!