One of many relationship dynamics that a polycule or a given hinge partner might end up balancing is different partners’ comfort, need for, or discomfort with power exchange or BDSM. There’s a notable amount of overlap in the polyamorous community with the kink community, so if your extended polycule is large enough, chances get pretty high that someone is going to be open about their kinks or interest in a power exchange based relationship. Even if it’s just a joke around Valentine’s Day about Secretary being a romantic movie, oblique references might be enough to cause discomfort that then has to be dealt with between other partners who don’t engage in that dynamic (or metamours; or leave a hinge who only has a power exchange relationship with one partner in an awkward position). Sometimes it isn’t awkward, precisely, but it’s an awareness people didn’t realize they’d be more jealous of than other situations.
There are a few strategies for addressing this that are most effective at turning around negativity about differences in some people’s interest in power exchange:
The people who have the power exchange dynamic can negotiate keeping their protocols out of spaces they share with other members of the polycule as much as possible so as to minimize discomfort on the part of people who aren’t involved.
The people who don’t have the power exchange dynamic can voice their discomfort with particular bits of the dynamic or protocols so that it’s clear what it is that’s an issue - is it an issue that your meta is sometimes waiting by the door for your shared partner to take their coat? Or is that not a problem, but it makes you uncomfortable that they wear a leather collar with a ring on it at events at your home? Bringing up the latter can save waiting for your partner to be a mind reader, and doing it politely isn’t “Yucking their yum” - it’s just expressing a concern or discomfort.
The people with the power exchange dynamic can negotiate changes to their dynamic as changes come up within an egalitarian container - because every change moves the pieces of their dynamic - and in so doing make sure they’re considering the effects on the vanilla relationships they’re in as well.
These seem simple and self-evident, but all of them are easy to overlook, especially during the flood of chemicals of NRE. It’s more common than anyone would like to admit to get carried away and go wild with a new relationship or new dynamic and get more than a little frenzied with excitement.
Taking care of the overall well-being of your polycule and not selling the farm off on a relationship with a decidedly different dynamic can be difficult, so folks can find these more intimidating or jealousy-inducing, in both directions. It’s a challenging thing to understand your partner having a relationship very different from your own with them. When it involves (or doesn’t) kinks that are different than your own, it’s icing on that challenging cake.