Saturn opposite Mercury
Balance in communication
You might really enjoy the way your friend looks up to you as a mental authority, but this dynamic is actually something to avoid. After all, you don't have all the answers to life, as much as you may try to pretend otherwise. To build a friendship on the idea that either person is more mentally capable than the other is folly, but this is just the kind of projection that will zing back and forth between you.
Besides, for your buddy to look up to you as their intellectual mentor is for both of you to undervalue their natural intelligence, their unique perspective and their singular ideas. Instead of playing into this by trying to dominate every conversation or pointing out logical flaws in their ideas, you should try to create a sense of equality by listening to your buddy, allowing them to express their thoughts in a natural and open way, and refraining from criticizing the ways in which they think.