Several months back S started a new relationship with a lovely woman, C. She was someone in the local community, although not close in orbit. They really hit it off. Hard. Fast. Scary. Here was someone I didn't know super well suddenly being elevated to the inner sanctum, close. It was at a particularly bad time for me, and I'd asked prior to this for several months of no major unavoidable changes. Apparently, this was unavoidable, and I was just going to need to figure out how to deal with the change, despite my reluctance to make the shift.
Cut to current time: Things are improving pretty steadily at this point, and one of the useful pieces that I'm taking away from the experience of adding a metamour when I was not well-resourced personally is an analogy about relative speed differences, and how to be mindful of each other in that situation.
Let's say that the relationship between the three of us is a car. When this relationship started, I put my foot firmly on the brake, and S on the gas, and most of the times where one of us was willing to let up, the other would push harder, giving us all whiplash. Uncomfortable, not constructive, and moving away from trust. Our mutual goal at this point is for each of us to let up on our respective peddle, and move the car forward at a mild pace without anyone panicking, or becoming overly eager. Then, as momentum starts to build up, we can increase speed slowly, without damage to the passengers, including C.
Now the three of us have started doing some combined time activities, where everyone is talking, holding hands with their partner(s), and generally desensitizing fears about the unknown, feeling prickly about all sharing space together, or being abandoned for the new shiny. Each small step makes it easier to reach out with direct communication, less hesitant to trust, and more willing to give.
Major kudos go to C for being willing to build things! I understand that, in the past, she's had some experiences with her partner's spouses/partners damaging the relationships she's been in, or being a trigger for instability within the other relationship. After having gone through that delightful ordeal, it tends to make one a bit wary about metamours that are interested in connecting with you personally, so my hat is off to her for taking a chance on me/us.
Together, we move forward, coasting a bit, but gradually increasing pace, depth, trust and intensity. Foot off the brake, foot off the gas, letting momentum of what has already passed advance things. Sometimes, driving 55 isn't such a bad thing. Eventually, we might even get up to freeway speeds! ;)