In a fantasy world where I could choose who I and my partners developed feelings for I would prefer additional partners to have their own primaries or other partners of equal significance to me (or my partners). For me, I think that would help me feel more comfortable that they understood the married/involved, but not exclusive, dynamic.
Dude has always respected my relationship with my husband, he understands that if MrS and I aren't "strong" then I can't lend my full attention to him when we are together. (In addition, he loves MrS in an utterly straight guy way - and reserves the right to still be friends with him if Dude and I ever break up). Yet still, he used to tease about us "running away together" (until I asked him to stop, exactly once, and he did - Dude may be the most stubborn, infuriating, jackass on the planet - but he does actually LISTEN to me, as does MrS, which is why I love them both).
I fear cowboys/cowgirls - I do (I admit it). I fear cheaters in poly clothing. OTOH if someone like NYCindie (solo, poly, thoughtful) showed up with an interest in one of my partners, I would welcome her with open arms - meet her or not on her terms, be friends or casual acquaintances as our chemistry and her comfort level allowed - as long as she were clear with them what her terms ARE. Most people (and I am not just talking polyfolk here) are NOT AT ALL clear about who/what they are or what they are willing to offer to a relationship. They don't know their own boundaries and are unwilling to consider the boundaries of others. I have worked hard on this myself - my boundaries are broad but firm. You can develop WHATEVER kind of relationship you want/can with me or my partners - over time, with consideration. What you CAN'T do is dictate that they (my partners) change/end their relationship with ME.
I don't want drama. I don't want anyone to get mortally wounded/traumatized. I want people that I care about, and the people that they care about to feel loved and cherished. I don't want to be sacrificed on the altar of poly to accomplish this. I am willing to undergo discomfort and hard conversations - but ultimately I deserve to feel loved and cherished as well.
Me: poly bi female, in an "open-but-not-looking" Vee-plus with -
MrS: hetero polyflexible male, live-in husband (22+ yrs)
Dude: hetero poly male, live-in boyfriend (3+ yrs) and MrS's best friend
Lotus: poly bi married female, "it's complicated" relationships with Dude/JaneQ/MrS (1+ years)
+ "others" = FBs, FWBs, lover-friends, platonic G/BFs, boytoys, etc.
My poly blogs here:
The Journey of JaneQSmythe
The Notebook of JaneQSmythe