Let's start with this; I am going to use a very typical idea of a relationship-male and female.
Disclaimer!!! I am going to stereotype you to death in most of my writing. I do this because this type of generalization makes it easy to work with mentally. Yes, I realize that people of all sexual orientations read this blog. I welcome you, I back your choice, and am sympathetic to your plight, but for the few that stumble along who are just working their way into this, I am going to be as simple as I can. Thanks for understanding.
Okay. Now, lets start with Dick and Jane. Dick meets Jane, they fall in love and they get married. (How sweet…) They have their 2.5 kids, and everything that all good suburban couples have. One thing is different, Dick and Jane are actually practitioners of BDSM. Dick is the Master (or Dominant, Daddy, um…whatever other term you may wish to use here…those are the most accepted, though daddy doms have a whole different brand of dominance. Anyway…) Jane is the submissive (do not apply the word slave here, we will cover the difference next time around).
Dick and Jane have some friends named Sue and Bob. Sue and Bob are in an open relationship; That is they have multiple sexual partners. Both Jane and Sue are bi-sexual, and have frequently spoken about the two lifestyles and about their attraction to each other. Both men are also interested in swapping partners, to whatever extent can be negotiated.
Dick is obviously interested in seeing his wife top Sue, Bob is not interested in BDSM at all, and is concerned that he will not know how to function, but is satisfied with simply watching the interaction take place.
Sue is interested in the sexual interaction, and feels safe with both Dick and Jane in a bondage setting. In this they have decided that Sue will be bound, and instead of Dick having any interaction with Sue from a sadistic standpoint (no flogging, no spanking, nothing that would be sadistic in nature) he will instead direct Jane, who is moderately sadistic, and will also be happy with the praise and dominance she gets from Dick in this interaction.
Thus far, everyone is happy, and all parties are satisfied with the arrangements.
This will continue for sometime, but eventually, Sue and Bob go their separate ways, and Sue will become part of the home that Dick and Jane share. In this instance, with Sue being the second woman, (again, this is the most common that I have seen, there are many other ways for this to work, so, remember, when in doubt, stereotype!) Jane will be the alpha submissive; she is dominant to Sue in any situation that would involve BDSM, or if the two decide to play in that manner with out Dick.
The beauty of this is that all three partners still have the ability to have other partners. Sue and Bob meet up regularly, Dick submits to Sue when he feels like it, Sue sees someone else all together here and there. The possibilities for this dynamic working for these four people are endless. Simply infinite. The important thing is that you have four people who love and trust each other, and who are open to those possibilities. The element of trust comes from open communication of which roles are assigned, which roles are open to movement, as well as emotional aspects that have all been discussed, agreed upon and are all defined so that no toes get stepped on in the process.
It is possible that all of these people have this life, and never sleep together, they could be room mates, they could be friends and nothing more, but still they could develop sexually to a place where they find only mental release with each other and little or no physical interaction between any of them occur. It is the love and trust that make a BDSM relationship a wonder to behold. The same can be said of open relationships, or Poly households. These things are truly a marvel to behold, because you find it so rarely, and you see this small group of people who love and care for each other so deeply. Neither is wrong, they can both be worked into each other perfectly, and fit like a glove.
