When I was with my ex gf who was BPD if I ever received a text she would think it was from another woman, or if I said something that was a normal comment, depending on her situation, she would regularly go into dissociate mode.
i think youre talking about dysregulating (emotions) as opposed to dissociation.
people with BPD traits have an above average fear of abandonment, which often manifests in jealousy. while it might be natural to have a tinge of jealousy watching your partner interact with whatever sex they are attracted to, that tinge of jealousy becomes an emotion in search of a reason (we often say around here "feelings = fact".
people with BPD traits also have a higher than average sensitivity to criticism or perceived slights. innocent comments (or not) can often be felt, and blown out of proportion.