In the poly world, a question like this sometimes emerges: “I’ve started talking to this new guy… he has a girlfriend but says they’re in an open relationship. I’ve never met her or talked to her: should I make sure it’s really okay with her before I go out with him?”
My answer is pretty unequivocally “yes.” People who disagree, or who have doubts, will usually lead off with something like, “He doesn’t need her permission to see someone else!” I get where that’s coming from: a huge part of the philosophy behind poly is that we don’t “own” our partners’ hearts or bodies. Also that love, affection, and orgasms they might give to someone else in no way diminishes those things they give to us. I’m fully behind both of these ideas, but. I still think it’s essential to verify that our partner’s partners are comfortable, or at least accepting, of our relationship with them, whatever it is.
It’s not about permission or ownership, it’s about caring. If a new partner is in a committed relationship, I assume that relationship is important to them. If I’m just starting to see someone, I’m going to do my due diligence to avoid damaging their prior relationships. Likewise, I care about the feelings and needs of their partner, even if that person’s a stranger to me. Because we share a lover, they are de facto part of my immediate community, and I’m not going to hurt them if I can help it.
There are also more self-interested considerations. Trust: if someone is going to lie to their committed partner, what makes me think I’m going to get the honesty and respect I need from them? Drama-avoidance: I don’t want to find myself in the middle of shouts and tears and betrayal. I don’t want to be hated by a whole bunch of people I don’t know. I would much rather conduct my life honestly and openly, and with respect for everybody involved, even if it means missing out on a few exciting relationships.