Glad to hear it wasn't as bad as what you first expected. In reading your post, what stood out the most was his shame. You didn't really get into the content, and I don't think you need to, but it seems to me that he doesn't feel safe enough with you to share this part of himself that he's exploring. I wonder if this is truly because he is ashamed of it within himself or if it has everything to do with the relationship.
I wonder if the content of this is something that you can change your perspective on - going far out of your way to avoid being the parent catching the child doing something wrong. Maybe even let on that there's something about it that makes you appreciate him. That you admire him, even if this doesn't appeal to you. I think he's fishing for this sort of attention online and if you can give it to him, so much the better.
Just some thoughts. Hang in there - hope the dust settles soon.
“No problem can be solved from the same level of consciousness that created it. ” – Albert Einstein
