Polyamory is supposed to be about abundance, writes advice columnist Eleanor Gordon-Smith. But your partner’s behaviour risks making it a zero-sum arrangement

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I have been in a wonderful relationship for six years. We are polyamorous and recently we have been thinking about marrying and starting a family. I think this shift should include stricter boundaries and safeguards, as carrying a child will be disproportionately taxing for me and I expect I won’t want to feel vulnerable or jealous. I also think children necessarily bring about changes in lifestyle, and I would be happy to put the promiscuity on pause. At the very least, I’d like him to steer clear of romantic connections; I’m much more open about him simply having sexual liaisons or flirting.

He will not commit to this, on philosophical grounds. He says I am his soulmate, but also that there can be many soulmates and that “nobody can promise anything for ever”. When I suggest this means we should not be primary partners so that I may pursue those milestones with someone who can give me the reassurances I need, he disagrees very strongly and asks me not to decide on the fate of our relationship without him.