Can I read this to mean that you are kind of the boss in the relationship? I've wondered about that with INFJ/INTP. "INF" seems so "soft", caring, classy, and likeable, but "J" likes to be bossy, order people around, impose its will, remind people of the chores they haven't finished yet, etc. It doesn't take any crap so to speak. Is that kind of how it goes? Is the J/P divide the biggest problem spot with this pairing in your experience? Procrastination and a "there's no rush"/"it can be done tomorrow" attitude on the part of the INTP while the INFJ has the "it has to be done now because I said so and I'm sick of this" approach?
That alone (if it's symptomatic of INTP/INFJ?), would cause me great strife in a relationship. I can't have someone ordering me around/telling me what to do as if I'm one of the children in the house. It just wouldn't go well.
I'm not bashing INFJ's here. In fact, I'm pretty sure INTP (or ENTP) with INFJ has great potential in most cases. I'm just wondering how the J/P plays out IRL.