Sorry to hear your H is pulling crap like this. Doesn't he know that most people aren't gullible enough to buy his statement of "those are old" (referring to the printed pictures) when the print date is right there?!!
Sorry for the vent...but I just got finished dealing with one of my best friends who divorced a man who displayed similar behavior...he was having a relationship with a girl from the time she was 13-16yrs of age. Things like this throw up BIG warning signs for me.
Now don't get me wrong, he may not be doing anything like that at all, I'm not trying to suggest that he is. But the fact is he's still doing what you and he are supposed to be addressing in counseling and his behavior just causes my spine to stiffen up.
One thing I wanted to see if you knew how to do, is check the history files on your computer. If you check the history on your computer and there's continually nothing there (if he knows how to delete those files, which isn't hard) that would be a suspicious sign that he's still going somewhere on the net that he doesn't want you to know about. If he doesn't know about the history files...then that's also an excellent place to go see where he's surfing when he's on the net
You can also view your "Temporary files" on your computer. Those will show images that have popped up on the screen, or that he's downloaded and many other things. Most people don't think about cleaning their computer out of their temporary or "cached" files very often. My best friend's ex would clean out his history file, but always forgot to clean out the "temp" or "cached" files...that's how I caught him sending erotic e-mail to a 13yr old.
Just some info on where to look...if you wish to use it.