Considering my two life options: kicking everybody out of my life who betrays my trust, or learning to repair relationships tainted by betrayal. The former option keeps everything temptingly simple, but on the other hand... nobody is perfect, and if I kick everybody to the curb after a single strike, that means I won't get to keep anybody.
I suppose that's an unfair way to portray it, though.
Generally I give people one opportunity to prove that an instance of awfulness is not reflective of their real priorities and values, because there are people who just don't think clearly enough or deeply enough about what they do, and it's possible to just hash things out with them and give them the data they need to be the kind of friend they want to be.
The rule is double-edged. On the one hand, that's basically the "take them or leave them" moment for the relationship, whether I drop them right that moment or not. Generally if I am going to ditch someone, that's when the decision got made, and everything in between that decision and its actualization? Just damage control, no matter how it looks. The other edge, though, is that I don't trust people until we have had this moment. How can I know whether someone really gives a shit about me and whatever relationship we have if they've never needed to demonstrate it? How can I possibly know someone until I know how they handle conflict?
Knowing who a person is when everything's going their way is not knowing them at all, because there is no healthy and reasonable way to keep them happy all the time so that I never need to know what kind of person they are when things get thorny.
I really do think it's when people show their true colors. Not in the "be perfect and never fuck up" period, but in the "well somebody fucked up so now what do we do?" period. Whether I have fucked up or they have, here is what needs to happen. Anything short of this is grounds for immediate friendship termination (with only a couple of exceptions).
Rebuilding trust is something two people do together. You just can't say, "You go off and become trustworthy and then come back and we'll see." It doesn't work that way.
You're needing to talk to each other, to share information about what things mean to you. You've got to talk about things that are difficult to say and difficult to hear and do so without making each other miserable. You've got to share hurt feelings without creating more hurt feelings. You've got to listen when you're itching to make yourself heard and make yourself heard when you're tired of talking. - Mira Kirshenbaum
Remember. Fail here by being a shitshow, and it's done. Succeed here and we're actually bros now. Remember that this is a standard I hold myself to as well, and that my refusal to implode is not a sign that I don't care, but that I care too much about solving whatever problem we have to collapse at this crucial moment.
It's a risky time. No matter which side I am on, it's the moment when I know whether to trust this person and accept them in for real, or whether they should be cut loose before they have the power to do serious damage. So basically, people have one chance with me to demonstrate that they deserve chances at all. If they use that first chance well, they'll get more (up to a point, until I see them squandering those opportunities).
The lovely thing about this approach is that it pretty well protects me from betrayal. I don't take too many emotional risks if I refuse to get invested until I've given someone's risk level a favorable evaluation.
When someone shows you who they are, believe them the first time. - Maya Angelou
It has a drawback, though. It means that the better I get at assessing who is likely to betray me and how, the longer I go without practicing dealing with betrayal. I think I deal with it okay, despite not having very many opportunities to hone my skills. Perhaps the definition of dealing well with betrayal
is knowing when the cost-benefit analysis tips in favor of just cutting them off, and then acting accordingly.
Every now and again I do wonder if I am missing out, but at the same time... I think I am generous enough. My life has a lot less drama in it than many people I know because "tends to introduce drama" is fully enough reason to show someone the door whether they need my support or have some other reason why I should keep them around out of pity. I'm having a moment of second-guessing that instant willingness to turn and sever, but deep down I'm still satisfied with my results.
Arrakis teaches the attitude of the knife - chopping off what's incomplete and saying: "Now, it's complete because it's ended here." - Frank Herbert