rofl Adam, I'm going to have to keep "GI Joe Kung Do Grip" on tap for future conversation.
I feel like "lack of passion" isn't a valid excuse. If there were a lack of passion, I feel, as Hammy did, that the problem would be getting aroused, not finishing. Furthermore, with the huge variety of condoms and lubricants and all that jazz available, I'm not sure a condom is going to be the issue.
I'm wondering if perhaps as Adam suggested that your bf is so used to the sensation from masturbation that the sensation from a vagina isn't...well, it's not what he's used to, in a manner of speaking. I've heard of that mentioned before, though largely I've heard it used as a sort of urban legend regarding masturbation. I have no legitimate backing to that claim.
That being said, communication is ultimately key. Have you spoken at length as to what he enjoys in bed? There could be, perhaps, a difference as to what he understands as "passion" and what you do. Furthermore, he should really reconsider the sex therapist...he needs to be willing to do what it takes to further your relationship together, and he needs to understand that this is a way for you two to overcome an obstacle in your relationship. Why is he so adamant about not going?
Keep us posted, and I do hope things work out for you two for the best.
Hugs,
Harley