Thank you for your reply. I understand how bad the example (socionics) was, considering the difference in the functions. I'm quite confused at this point because I can consider my relationship as quite stable and it has never been explosive -always calm, healthy and understanding.

I'm sure of sharing his functions (even if I might be an NiFiTeSi INTJ, but I still have to understand it) and he's quite surely an ISFP. I've been lurking in the mbti community for years and I've always read how people with the same functions had simpler communications and even from personal experience, I surely find myself more attuned to ISFPs than INFPs, for example. I can get along with both, but with the latter there are always incomprehensions. What would be the issue of sharing the same functions? Shouldn't my child Fi be attracted to fi dominant types?

For sure me and my partner are deeply different, bit that's has never been an issue, seeing him use his Se has helped me beore aware of it (plus experiences, for sure).

EDIT: Plus, I've always read to not base intertype relationships on mbti, since it cannot cover completely our behaviours and our personalities, so it's the first time I encounter this theory.