He googled "cartoon character's" bum and it came up with porn. I found it because he'd been using the tablet in his bedroom and I checked the history and saw it. Obviously it's a big wake up call and I have added filters and he won't be having any unsupervised access to the tablet again whatsoever. But I need to talk to him about what he saw tomorrow morning and why I don't want him seeing stuff like that but gently iyswim.
What do I say?