When it comes to seeking variety, Subshrink11 sums this up nicely, “I'm an s-type and often have more that one D-type in my life. The reasons are similar to to why I'm polyamorous in general. Each partner has something different to offer. I many want more than one gender, more than one power exchange dynamic, etc. I have various tastes, and different Tops have different skill sets.”
She also brings up an excellent point — while people are often looking for different traits from different partners, when it comes to kink, these differences can be even more explicit. Maybe one top or Dominant is skilled with rope, while another is a master of impact play. Maybe one is more psychological with their play and the other is more physical. No one person can ever be an expert in all kinds of play, so having more than one Dominant or top means you can experience a variety of forms of play, while still doing so within the structure of a relationship.
Adding D/s to the open relationship mix can certainly make things more complicated. Either relationship structure on its own can have complications and combining the two can create unique challenges. There is a book on this very topic: Power Circuits, Polyamory in a Power Dynamic by Raven Kaldera which offers some guidance in this realm.
Aurora speaks to some of the challenges people face when having more than one Dominant, “For me, I don't know that I specifically set out to have more than one dominant as much as it has been an extension of being both submissive and polyamorous. When I started seeing the newer of my two in-town partners, each one had their own separate style of dominance. After a while, it felt too hard to manage the different demands alone. Recently, [my dominant partners] have started talking more and collaborating on dominance together, while still maintaining most of their independence. Having this added line of communication has been amazing!”