Good. Though I wouldn't have minded seeing what it was about.
When I was a child there was no porn around, at least not visibly, and I wouldn't have known what it was. I do sometimes wonder, had it been available, if I would have been curious and I imagine I would. It may well have scared or horrified me but if it had just been two nudey people I might have found it interesting.
Well, we'll never know which is perhaps just as well :-).
However I don't think we can be too hard on kids if they do look, it's not their fault porn is all over the place nowadays. We have to try to educate them about it.