Why don’t you just warn him about Picasa? Just in general. You don’t have to let him know you know anything. Just mention it as kind of a computer security “tip.” I did something similar when I discovered porn on a friend’s computer. He may have suspected I knew but he appreciated my discretion.

I’ve followed this thread with interest. While I’m not for sticking my nose into other people’s business I sense that you are looking for a way to “break the ice.” Mentioning the porn you found would be a bad idea—very bad. But you might strike up a conversation about transsexuals with him. How? Well…

There have been many movies and television shows featuring transwomen as major characters. You could always strike up a conversation about that. For example, I really did use the “CSI” episode that featured Kate Walsh to “come out” to a couple of my friends (Season 5, Episode 8: "Ch-Ch-Changes"). There are plenty of examples. There is even a thread (or two) on this forum that discusses transgendered themed movies and shows. Whatever you decide to do, good luck!