That isn't necessarily the case with BPD. When we say no, it can often times be a "test" if you will. I've caught myself MANY times doing this kind of "test" with my current boyfriend. And most of the times, when I realize it, the "test" is almost over and he either passed, or he's too stubborn to actually fall for it and passes but without taking the action in the way that I am more comfortable.
Many people will call this manipulation. But honestly, those with BPD tend to SUCK at manipulating people. This emotional manipulation that BPDers do to others is completely unintentional. I've tried, very poorly, to actually manipulate others, and rarely does it ever work. But when I am triggered and I am vocal about it (lashing out either to myself or others) and somebody does see it, that's when I somehow am able to manipulate... I don't take that chance in trying to manipulate because when I do (I did it a few times before) I end up feeling guilt ridden and a monster for doing that to somebody that cares about me.
I am more under the impression that your guy is only testing you to see if you really WILL stay next to him through thick and thin. Often times, he may have heard that promise from many other women and obviously he feels that they lied and "abandoned" him. The thing is, our fear of abandonment, is often times VERY illogical. So we want our partner to prove to us that they are serious. That they do love us. That we are good people. But no matter how many times they prove it, we still feel like it's not enough, and doing this deadly dance is what causes our illogical fear to become logical when our partner realizes that there is nothing they can do to make us happy and leaves. Thus we cause our loved ones to abandon us because of the hatred and disgust we feel for ourselves. For me, often times I'm just like, "I knew you would leave me. I told you that I was a horrible person. I don't deserve to be happy. I don't deserve to be loved. Everything bad that happened in my life is my fault and I deserved every single moment of it. People only pretend to care because they pity me. I thought you were different, but I was wrong. I'm going to become the crazy cat lady with 5o cats and die alone".
I also get the impression that your guy may be ready to actually get help but doesn't know where to start, or that he may not be ready because of fear of change. I know some with BPD, myself included, have a fear of change. I developed mine because when I was very little, everything was constantly changing. My father would constantly be away (at work and with an other woman) and for a few years in my life, he was gone. But when he was there, we often times moved around because of his work. So I would always "make" new friends, but then suddenly, I would have to leave, or they would have to leave (my father was in the military so we lived on base most of the time) and I felt like I was abandoning them, or they were abandoning me... Even at an early age. Then my parents split up and my father, ended up leaving my life, only stopping by every so often. He got married to a horrible woman who has two children, and I feel like he replaced my mom, my sister and me with them. He rarely talks to us. And with me, it's even more pathetic because I live with his parents, and he calls them more than he calls me still.
I really don't see this as you chasing the white rabbit. I think that this is a good time for you to show him that you will be there for him, but because you are now aware of the ""manipulation" those with BPD have, you can at least try and look t it as logical as possible. Know when to put your foot down, but not in a way where he feels like you are leaving him. And the fact that you are very willing to actually look for information about his condition and wanting to help him is good. I am kinda envious of him because he has somebody that does want to learn more about what triggers his moods, and want to help him sort out those feelings... But then again, my boyfriend just doesn't want to learn about BPD because he knows about his manipulative behavior and knows that it will cause more harm than good.