Am I reading his reaction inaccurately?
No. "Christian" music is part of Babylon the Great - False Religion. When I was in I HATED Christian Rock. Id rather listen to Mexican music then Christian Rock. Its all part of false religion. Thats how they think.
Now I don't like Christain Rock for other reasons. If he's baptized as a JW then he shouldnt have anything to do with you as you belong to Babylon the Great. Unless he's fading from the cult, I'd sugest you find a new boy friend.
If you don't agree with the lyrics, isn't it still okay to appreciate the melody or beat?
Not for JW's