In the Ghost Hunt anime, in the "The After-School Hexer" story (episodes 7-10), Naru shows that he can bend a spoon using psychokinesis, but asks Mai not to tell Lin he did so.
It is revealed at the end of the first (and only) season that
Naru has tremendous psychic powers, that are too much for a human being to control, therefore he must not use them. Lin looks after Naru and is the one who has told him not to use his powers.
But later in the same story arc, it is revealed that
Naru used a trick to bend the spoon. There was no psychic power involved.
So why would he need to hide this from Lin?