Yes, I would consider a rupture to be something that leads to a breakdown in trust. A T suddenly tightening or otherwise changing boundaries is something that has led to a rupture for me in a few cases (once with ex-T and twice with MC). A T saying something that feels really hurtful is another reason--like when ex-T said, in a harsh manner, "I can't be your mother or your friend!"

It's something that makes you doubt the relationship and/or changes your view of the T. It could be something that kind of rubs your face in the one-sidedness of the therapeutic relationship.

I think transference can make them much worse, because then the rupture often isn't just about the T, but also bringing to mind something from the past. I told MC recently that it felt like he had retraumatized me in suddenly telling me I had to reduce contact with him (partly in response to my saying I loved him). It brought to mind other times I'd been rejected for expressing my feelings. And it especially hurt because MC always would say that any feelings are OK, how we aren't in control of them. And he knows how sensitive I am to certain things. So for him to do what he did...then try to claim "Oh, I wasn't trying to push you away..." it seems much worse. (As compared to, say, a friend doing that.)

I think in some cases, working through ruptures can ultimately make the relationship stronger. But other times...I think they can shift things in a way that permanently changes the relationship--I feel that's what happened the most recent time with MC.

Sorry, I'm rambling now. Growly, I hope you're able to work this out with Kashi. I suspect much of it will come down to how he responds, whether he seems to understand what's upsetting you, whether he seems truly sorry, whether he owns his role in it, and what he does to repair it. At least, that's been the case for me.