3 possible reasons
1. He was testing my faith, patience and trust in him...despite his words.
"Even though he says he doesn't know anything about the film...how could that really be? Of course he read about it!"2. His knowing the film was okay (without my knowing) put him in control and in position of some power.3. By claiming he didn't read about it/know about it...he would gain in my eyes, by having the 'touch'. That is, I might begin to develop an opinion of him that he's to be trusted about his good intuition, choice, etc. And the state that would be created by the unfolding of the not-scary film (when I was afraid it might be) would somehow be more powerful.