I would look into if your partner has NPD traits. Its super common for us to get attached in this push pull manner. This sounds to me like some of the transactions described in the Narcissistic Borderline Couple
Something similar happened to me and my ex when I was first diagnosed. Those of us with BPD are really sensitive to invalidation and these type of comments can be used to control our behavior in ways that are against our values and without our consent. This type of behavior is not reciprocated because of our attachment needs, and it becomes massively one sided. I would definitely bring up these transactions in therapy and call out how unfair it is when it happens. Good luck.
Just wanted to throw out there that relationships between people with BPD/NPD are extremely common and have complimentary pathologies that keep the bond extremely strong despite it not being a healthy bond.
There are complex reasons for this, other than "supply" and thinking that people with NPD dehumanize people with BPD. In fact, they humanize people with BPD more than the typical neurotically organized folk.
Don't use being triggered as a reason to perpetuate ignorance.