I have been in a similar for a few years. There's a guy I just cannot cut off emotionally and I don't know him all that well! I tell him everything about myself; all my feelings, my dreams. I used to have similar doubts about whether I'm doing something stupid, but that friend of mine is a reliable person and I just decide that it's okay (he's likely an INTj).

As an INTj, you are quite careful with selecting friends, your friend is likely like mine -- won't go around and gossip about you. But of course, don't get too carried away. Keep an eye open for potential real romantic relationships.