Yep, back in 1976 my older sister caught me jacking off to a photo of her best friend while I was in the bathroom. My sister just rolled her eyes and said put it back when you're done. I was 14 and my sister was 17. Nothing was ever said until about two months later when I found a card in my room. On the card was written "Thank you, you're the best" and a kiss at the bottom. Apparently, my sister told her best friend at some point. It's never been mentioned since.