I could really use some insight because I don't want to fuck it up.  


So a few folks important to me have BPD, but one relative is not in a great place &amp; frequently experiences genuinely traumatic delusional episodes.  They've been to a therapist long enough to get a diagnosis, but don't seem to be in treatment, and have taken offense to the suggestion in the past.  So, it's not really up for discussion, and they may not have a metric for recognizing false memories.  Neither do I, for the most part, but periodically, they will confront me about horrible things they remember me saying or doing to them - things I have racked my brains over but can't remember at all.  (I have my own history with depression/anxiety/an-ex-telling-me-I'm-a-bad-person, etc, and used to be one of those people who always assumed everything is my fault.  This isn't about me, but still.)  


So far, if I'm pretty sure what they're saying I did is false (it's less "accusing" and more "seeking closure.")  I usually try to mention that I can't remember that happening, but try to apologize sincerely.  


Is this helping or making things worse?  I don't want to "confirm" a hurtful false memory, but the emotional trauma they feel as a result is very real, and sometimes apologizing is all I can think to do.  


This relative is an adult, and not a threat to anybody, so unless *they* decide they want treatment, there's no way of "making" them get help managing these episodes.  


Recently they told me about some truly awful things that they remember me saying.  It was my fault, in the sense that I accidentally triggered an episode of some sort while we were talking about other things.  However, the scenario they described involved a third party that we've never really hung out with together.  I felt horrible, but obviously they felt much worse, so I did the usual "I can't remember that but I'm really sorry, that's so shitty."  


I'm afraid of spending the rest of our lives accepting the blame for things I didn't do, and seeing them be hurt by this shitty asshole version of me in their memory.  I don't know what else to do.  


TL;DR - Someone in my family has untreated BPD and experiences traumatic delusions/false memories.  Sometimes they confront me about terrible things I didn't do.  Saying it was a delusion is off the table.  If you've been in their position, what would you want the other person to say to you?  What would help?  


(Apologizing all the time kind of sucks for my mental health, but I will a thousand times over if that's what they need from me.)