What he's doing, is considered coercion and manipulation. As far, as I have ever known, clinical depression and BPD, don't usually co-exist. I've heard it like that before, but I don't feel those two are co-morbid diagnosis,(could be wrong, not being a professional), but even if you do have the rejection trigger of bpd, I feel, even someone without BPD, would question themselves, in your situation.

Of course, it's tougher to want your friend to co-house with you.

Open relationships, require mutual consent. And I have read, here, on PC, people saying, that those that they know that are in these types of relationships, it's because there is much trust and honesty, etc.

Freebies, because he has a medical E.Dysfunction?

He could have considered the long term effect of not having had previous partners, before committing himself to you, honoring himself to you in a marriage, that I imagine, you meant to be monogamous, from the beginning?