I think what Fi + Ne does is explain itself through metaphor. It's not all that articulate either. I often feel like I have no clue how to express what's inside, but then I'll latch on to something outside of me that I think explains it well. Often it's not all that conscious of a process. For example, I do visual art and I was drawn to this photograph of a man who recently died after a deep sea dive attempt without oxygen. He had this look of panic on his face and I wanted to paint it. Then I started to think about diving deeply with no external support and pushing yourself to this level of interiority that can eventually kill you and I thought, hmm, that explains how I feel a lot of the time.
I read somewhere that ISFPs often have difficulty verbalizing while INFPs often think they have more difficulty than they actually do. Maybe that's the case.
As far as the OP goes, I'm married to an ESFP and I get where you're coming from. I didn't know about MBTI but when we started dating I thought he lacked 'something'. But I loved him so I got over it. I also thought this after we were married for seven years, and that our extremely obvious differences were irreconcilable. But sometimes you do connect with people in certain ways and not in others. I feel like most of our connections are nonverbal and unarticulated. I kind of like that, actually. It makes it more mysterious and complicated. We will never quite figure each other out. But we do share Fi and we do share the pov of an extroverted perceiver, so we aren't all that different. We both like novelty and are pretty open minded.
Also, my kid is an ISFP and we are very close. He is the coolest and I admire many of his qualities. His imagination works in ways I can only dream about. I definitely have more in common with him than, say, most INTJs. (Nothing against INTJs or anything.)