I believe I can help you with your concern
I am so sorry that you are having this issue with your boyfriend, i can imagine how distressing this is for you
May I ask, for how long has your sex life with your boyfriend been diminishing?
And is he taking any medications for his Borderline Personality Disorder (BPD)?
We've been together for about 2 years. The sex was great for about the first 6 months and then slowly got to be less and less. For about the past year, it has been very seldom. When it does happen, he's not "involved".
He's not taking medication.
And what about your relationship outside of the bedroom? Would you consider you two emotionally close?
Yes. And he says that that is what is important. Though I completely agree, and I so value our emotional intimacy, as an adult woman I do have sexual needs. It's difficult for me to only have emotional intimacy without the sexual bond. I just don't understand how one can love someone "too much" for sex.
That is an odd statement by him, I would agree. What do you know of his past sexual relationships? I know men do not often talk about this with their current girlfriends, but I was curious if you knew anything about his past sexual history at all?
I know that he is sexually promiscuous when he is single. He says, though, that when he has been in serious relationships, this is the reason they always end. He was previously married and he says that sex was there biggest difficulty (him not being able to give enough in this area).
So it is possible that for him sex was just used for physical pleasure and just used to please him, not caring about the other person. But with you, he genuinely feels love for you and when he has sex with you, it reminds him of his promiscuous past possibly and how he "used" others for his needs and does not want to do that to you.
This happens with some men who have a history of promiscuity or poor past sexual relationships. The best way to resolve this usually is with Cognitive Behavioral Therapy (CBT) with a therapist/psychologist that specializes in Sexual Therapy
CBT has a premise that your symptoms are caused by negative thoughts, so if we change your thought process to be more positive and objective as well, then your symptoms will lessen. So this will help him see that sexual pleasure and intimacy and coincide with emotional intimacy as well, while subconsciously he separates the two as polar opposites.
If he refuses therapy, then there is no hope for change? I don't understand how he can know something is so important to me and not be willing to compromise.
Some individuals with BPD have a difficulty seeing their faults and that is why they refuse to go to therapy. I agree that he should at least consider therapy or at least couple's therapy, so you are there as a support for him because this is very important for you. But I am afraid that without therapy there is less likelihood that his behavior will change unfortunately
Is there anything I can do as his partner to help in this area?
Well you can equate emotional intimacy with physical intimacy, by verbalizing how the two are linked and even though he has a past of sexual promiscuity and non-emotional sex, does not mean that sex with you will be non-emotional and on the contrary it can be very emotional and with that more exciting. By pointing out these negative thoughts he has regarding this and showing him alternative/objective thoughts, this will help him understand more and hopefully will change his way of thinking. But once again he must be motivated to change and if he is not then I am afraid anything you say may fall on deaf ears.