Well how about this, when I am gone babysitting to earn some money that we don't have and just recently I left the house to grieve for the death of my grandfather. Both of those times, he was viewing porn. That shows no concern for me at all.

Well - like I said - its only my opinion, but checking to see the times he looks at that stuff online, you can always try to catch him at that time. I dont want to incinerate the poor guy, but if he suddenly has zero interest in sex now... dont you think this is a warning sign of some sort?