I don't remember if there's a standard advice for this in a rs with a person with undiagnosed BPD.
When you're not in love anymore, but still together. What do you respond to someone asking you if you love them? Lie, be honest, avoid, give unclear answers?
I don't like the feeling of not being honest, so I probably avoid the questions by giving unclear answers. Being honest leads to chaos and I don't have any spare energy for that.
I just don't think I'm doing a very good job right now. Maybe the answer is that if you don't feel love, you should separate.
Would the advice be different to a person in a "healthy" rs feeling like this.
Be honest, but very tactful, and reframe it in a neutral to positive light, in order to minimize triggering them [chaos as you describe it]. They are likely asking since they sense a change in this towards them, in effect you will be validating them.
Being mindful, there are many different kinds of love:
Eros
Agape
Storge
Philia
Romance
Infatuation
Consummate love
Fatuous love
Companionate love
Unrequited love
Platonic love
Unconditional love
Non love
Passionate love
Obsessive love
Describe the unconditional love (if true) you have for them, even though your infatuation/romantic/passionate love has diminished (based on your description, let me know if I am not right) for your pwBPD.
If you word it that you 'no longer love' them, it will likely trigger their irrational fear of abandonment, and there will be a good chance a borderline episode will happen [chaos].
In a normal relationship you would do something similar if you feel that your relationship has expired and you need to move on. Be 'kind' and not inflammatory.
