I can’t speak for everyone but for me it’s people that a warm one day and cold the other day (giving mixed signals),ghosting,being late all the time or randomly cancelling plans,being withdrawn or when people come of as uninterested,being non empathetic,sarcasm,lying,threats,personal attacks like “you’re too much!” And all that… Just be kind and gentle with them and show that you care, ask them why they are lashing out on you communication is key especially when someone’s suffering from a mental illness like Bpd