My Grandad has been taking naked pictures of himself?

My grandad (89) HAs been taking naked pictures of himself and putting them under my pillow. It's been going 12 years now, and i've finally realized that it is okay to speak to people about this. Don't jump to conclusions about gramps, he's an amazingly talented and flexible guy. I don't know what I'd do without him. The pictures consist of my grandad posing naked with my teddy bears in various positions around his body. What if my boyfriend found them or mummy or daddy. i don't know what to do, i like the photos but I don't want to let anyone find out and get grumpy grandad down. I'm scared of what these pictures symbolize and wether he is trying to get me to do something strange with him! xxxxxxxxxxxxxxxxxxxxxxx