I've been asked to write more frequently in here, and believe me, there wouldn't've been such a big gap between postings if I hadn't had my heart broken. That kind of thing tends to crimp your writing and most other creative outlets quite severely.
So today's topic is one that is close to my heart and one that there are many different impressions about. Getting along with your partner's partner... is it important?
My answer is FUCK YES! With all the extra emphasis that capitals, bold, underline and italics can add to two words... oh I can't underline... well you get the idea.
Polyamory lends itself to many different types of relationships developing which is a good thing. Some may be casual, others more serious. No matter how important each relationship is to your partner, it is important that you get along with their other partners. (I know I could just assign a gender here, but I can't be arsed just now, so deal with the incorrect "their" for the moment).
Remember when you were back in school and had a best friend. Remember what happened when you best friend had a falling out with one of your other best friends and you were forced to play sides or choose between friends. Remember how destructive that was... well poly can be that bad if you aren't mature about it and communicate and work on getting along.
Asking your partner to choose between you and someone else because you don't like them or are insecure about that relationship is a recipe for disaster. I've told my partners that to ask me to choose is very likely to mean that they lose. Being polyamorous is all about positive choice. Being asked to choose is about negative choice...
This post isn't about communication or choice, that can come later, so I'll get back to my point. I've been the pivot, pointy end of a V relationship where my two partners weren't getting along and I've been at the end of a V and not getting along with another partner, so I am speaking from experience here about how important it is that everyone does their best to get along.
You don't have to be best friends with your patner's partner, but not hating their guts and actually having an avenue of communication open if its needed is important. If you can be best friends with your partner's partner, then that's great, but if not, as long as you can be friendly it will mean a huge amount to your partner.
In a healthy relationship you want your partner to be hapy and your partner wants you to be happy. If you are not getting along with another of their partners your parter will feel the tension. They'll probably censor what they say about their day, be cautious around you and that runs the risk of damaging the relationship you have with your partner because you will know that they aren't being entirely honest with you, know why they aren't being honest with you and that tension will be felt.
If the falling out between the partners is shortlived, then it goes away and people are ok. If it's unresolvable as far as the partners are concerned, this is where the pivot has a role to play. When my partners weren't getting along (briefly) I ensured that they knew it was important for me that they got along. I encouraged them to talk to each other, to extend the hand of friendship and forgiveness, and explained that them getting along added to my happiness. They both understood that my overall happiness was impacted them getting along and so worked on getting over stuff... and did so.
When I didn't get along with my partner's partner... then that particular partner told me that he didn't mind if his partners didn't get along. This was really hard for me to deal with as it was the complete opposite of how I viewed polyamory. I was constantly afraid that he'd choose sides in the conflict, that the other partner would influence something somehow, that I'd be perceived as being difficult or whatever. I didn't feel that my concerns about this were really heard or understood by my partner because he didn't work on sorting out the conflict. He didn't encourage each of us to talk, he didn't explain to me his partner's position and I don't know if he explained my position to his partner. I felt that I had no way forward in resolving this and he didn't help me.
Polyamory is difficult enough without adding conflict between partners to it. So, I strongly recommend you work through any conflict you may have as quickly as possible. If you can't sort it out yourself, ask your partner to help. If you are concerned that your partner may not be the best help, find someone you both trust to help mediate, or meet somewhere public and just talk about the issues between you, how much working through these will make your joint partner happier and how it will make you both happier. This requires ownership of your own issues and maturity to acknowledge your own fault in the conflict.