So, yeah, when Fi doesn't say much, the Fe user sometimes might feel like, "Oh well, I guess I just won't use Fe with this person anymore. We just won't let each other know how we feel - we won't communicate on that level - we'll just stay to ourselves." If she's going to stay quiet, then so will I. Cuz, in the long run, I can't keep expressing affection and compliments and love and all those things if I just get "Thanks" in return. Instead, I'll just shut down Fe and we just won't talk about those things. It's gotta be a 2-way street, mutual communication.
Edit: And I don't say "I'll shut down my Fe" as a way to punish the Fi user. It's just that nothing is being reciprocated so I feel like I'm a broken record - always expressing myself, while nothing is said back. So, it's like "why bother?"