Do their friendships ever work out

Made the mistake of becoming friends with a guy with BPD. I really liked him and cared about him. His boyfriend told me he was being emotionally abused by him- I reached out to his brother to let him know that I felt the abuse could escalate before breaking off contact with both of them because I felt the whole thing was very mentally and emotionally draining and unhealthy. The only reason I reached out to the brother of this guy was because the brother told me I was his only friend and he also has autism. I also could no longer stand the guy with BPD constantly complaining about his boyfriend for hours and hours on end (up to 4 hours and never once asking how I was doing, just trashing his boyfriend) . The guy went through his boyfriends phone and asked why there wasn’t a text thread between us- the boyfriend admitted that I said I was distancing myself from them and that I asked him to delete the texts (which wasn’t even true)- the guy with BPD further went through his boyfriend’s texts and saw I contacted his brother. They sent me a very upset message claiming they felt betrayed . They are now messaging people in the community and trying to character assassinate me- fortunately, the people receiving this messages just view it as very unhinged and childish behavior. What can I expect from this person moving forward? It’s very upsetting and unfortunately I can’t avoid either of them as they live close by.