Socionics isn't gospel, if you don't like other delta's then don't date them and feel free to match up with other types and perhaps reconsider your own typing if you feel this way with most delta's and not just a select few individuals. As to why the SLI cut ties, I know that I myself would feel insanely uncomfortable/embarrassed being around a friend after admitting my feeling to them and being rejected, to the point where I would consider avoiding them to avoid feeling said discomfort and embarrassment when around them and assuming they probably feel the same way. Romantic rejection from a stranger or associate is one thing but a friend is just oh God. So yeah, I don't know details or anything or the circumstances of how he's a narcissist but just saying why I as an SLI would consider cutting ties over that.