Oh dear. I'm a female, dated an INFJ for a year and a half in total (six months first time, a year the second time) though we knew each other for five. It didn't end well at all. We broke up because he hit me and I don't take that kinda shit.
Main relational difficulties were that we were together because I was in emotional distress and he wanted to be my white knight in shining armor. We were not at all healthy for each other. Look up the song Tomorrow by Chris Young if you don't mind a spot of country, that song is a pretty good idea of a relationship between an INFJ an ENTP.
I found myself growing in Fe maturity, but I never desired to be like him. He's are even less made for this world than I am, he was pretty much permanently miserable with no hope for his future, and when I checked in with his roommate (my friend still as well) he's just as bad as ever. He has no way of being content in himself. That lead Ni is not enviable. He wasn't as bad as other ENTP's seem to see INFJ's as. He only tried to tell my own feelings a mere handful of times, mostly because I asked him what my feelings were often enough. If he told me something incorrect about me and I told him it was wrong, he took my word for it. We were good in that way, together. He understood and respected my superior Ti, and I the same for his Fe. His selfish belief in his own righteousness was strong, but it wasn't stronger than his idea of how intelligent I am. So I suppose in a way you could say we grew to be a bit like each other. I learned the use of Fe and could appreciate it, and he knew the use of Ti. The couple of times he did step out of line in regards to his thinking he , I quickly demolished his arguments. I remember only one time clearly enough to recall. He'd said he knew me better than I did, so I asked him which leg my birthmark was on and where it was. He had no idea.
Protip to arguing with INFJ's. Don't even attempt to go after their Ti, it's a useless effort. They're masters of suppressing Ti with their Ni. No, you need to go after their Se. With our Ne we're pretty good at noticing things when we pay attention, and if it's a matter of winning an argument, then we do. So I was quite excellent at shutting him down when he went too far. Just bring up something Se that I used my Ne to find, and he couldn't say a word. Hit 'em where it hurts.
The main relational difficulty was honestly that he never did get over that I broke up with him the first time for no reason. I'd just felt uncomfortable in the relationship for some reason, and that's all I could tell anyone at the time of why I broke up with him. I now know it was the religion difference, he wasn't just Jewish, he was anti-Christian. I hadn't realized the depths of his hatred for my religion until he made it clear that he could never respect someone who was Christian. He believed my religion was a brainwashing lie, and that anyone intelligent couldn't stay a Christian after seeing the "truth".
So in our whole second time in a relationship, he was uncomfortable with me once I got over my panic attacks and PTSD and started going out and making friends other than him again. As I got more and more freedom he pulled tighter and tighter, until he finally snapped and hit me.
It could never have worked. He was fun, and I enjoyed spending time with him. And INFJ's give the best hugs, it sounds strange but I think I miss his hugs more than anything else about him. But he couldn't understand himself well enough to know why he was growing uncomfortable with me, and he didn't communicate that to me. But in the end, even if he'd overcome his problems with trusting me, it still wouldn't have worked- he simply could never have gotten over his problems with Christianity. I mean, sure, people can thereotically change, but man... I sure would be surprised to hear he ever does. And I'd never be with someone who disrespected me based on my religion. That's his problem, not mine. I'm happy who I am and he can take his righteous dick and go fuck himself.
Also, he was the BIGGEST ASS after the breakup. And I don't usually use caps lock. He did his utmost to hurt me, and some of it worked, also not an easy task. He wanted me to feel as badly as he did. Of course that was doomed to start with- he felt more in a week than I've felt in my life. Maybe a month, come to think of it, that depression I had in high school was preeetty bad. Didn't stop him from trying though.
I would 100% never recommend to any ENTP dating an immature INFJ. Parts of the relationship were great, I really enjoyed having someone to explain my emotions to me, and our conversations were great. We were comfortable around each other in a way I've never been with anyone else. It was the mixture of Si and Se- I knew the feeling of his body so well from our years of hugs and occasional ninja fight (I always got up close and personal in that game) and wrestle and I imagine his Se with me gave him a similar feeling from the way he interacted with me. And he was pretty good at sex. So, if you find a mature INFJ that doesn't let their Ni destroy their Ti, and has worked through their Se issues... Maybe you should give it a try. But with great caution, friend. INFJ's are ridiculously horrible people, the worst I've ever known. Psychology studies agree that emotional damage, especially when purposefully aimed to hurt you by someone you cared for, is more damaging than physical. Personally I was much more offended by his lack of an apology and regret after hitting me than the actual hit. I wasn't badly hurt, it wasn't the physical that made it unforgiveable, but the fact that he saw nothing wrong with losing his temper and getting physical in a fight. And it was also what he'd said immediately after it to excuse himself. "It wasn't a hit, it was the tap you'd give a dog that wasn't listening to you." Oh, well defended there sir. How can I be upset with you after that stirring defense? Calling your girlfriend a bitch that needs physical disciplining when she disagrees with you, yes, you clearly thought that metaphor through.
I'm still surprised that I didn't punch him back. I only didn't because of the extreme shock of the event. I never, ever would have guessed he'd ever do that. He's lucky for that. If I could do it over again I'd probably beat him pretty bad, to be honest. But maybe that's because I also now know how unjust his post-breakup behavior was.
Seriously though, that post-breakup behavior was far worse than the relationship was good. I'm not even counting the reason for the breakup here, just purely based on his post breakup manipulation attempts. It was not even close to worth it from that. I don't care what people say about love being with the pain of losing them; not true with INFJ's. They will make you regret not listening to this piece of advice if you date an immature one. I'm giving them the benefit of the doubt, I'm sure they're capable of working through immaturity to reach decency in a relationship. Have I mentioned yet you should watch out?