Hi,
My partners and I live together on a temporary basis. The two of them had been together for a year, and I'd known them both I dated either of them. We've been a triad fro a few months.
Chronologically speaking, I don't see your position within the partnership as being terribly less "established" than theirs, considering your partners have only been together one year and you say you've been with them "a few months" - at least, not long enough for your partners to be SO very used to being a twosome that "couple privilege" would come into play without them being aware of it, as is often the case with couples who've been together for many years then bring in a "third".
One of them, late at night, told me they wished to propose to our partner. This freaked me out, as it was late to get such news. I also thought I had made it clear that I was against marriage and I wouldn't want to in a relationship with someone married (personal limits). Once it was discussed with all three of us, we all agreed marriage was off the table.
You're correct in describing your attitude toward marriage and not wanting to be involved with anyone married as a personal limit. That is YOUR boundary, and it's your right to stand firm on this.
That said, IF your partners had had a strong desire to marry each other, it would've been their right to do so. And if, after discussion with you, they couldn't be swayed from their plan to marry, you would then have to decide if you could live with that situation after all, or whether marriage would be a deal-breaker which would lead you to break up with them and go your own way. For the moment, it seems your partners have taken your wishes into consideration (albeit, belatedly) and decided to maintain the status quo.
The second major incident occurred recently. I've been living with them on a temporary basis. I had made an effort to find a place near their's so that while we could achieve some space, I would still be close. The other day the two of them announced to me they wanted to move out of their place and into a two person apartment, far from where I had been looking. I believe there was an expectation I would help them move, and make them a home I would not be apart of.
Your partners' behaviour in THIS instance seems less caring and respectful of YOU as a co-primary.
I assume they were aware you have been looking at finding alternative accomodations nearby and the reasons why? Obviously, from a practical point of view, it makes sense for you to live close by, if possible. It seems somewhat thoughtless if not downright rude to NOT consult you about their change of plans AHEAD of time, and preferably involve you in these discussions from the start.
Have you asked them why they decided to move some distance away from where you've been househunting? Without being privy to the work/financial/family/health situations of each triad member, it's hard to say if they have good reasons for wanting to move to a new neighbourhood. YOU need to find out what these reasons are, and why your own plans weren't taken into consideration before you can judge your next move, in my opinion.