My much younger than me little sister is 10 years old and has been taking sex ed. She seems to have been made aware of male masturbation for the first time. While she's probably heard of it before, I guess it's something she's never really thought of before and she's understandably curious. She asked me to show her what it is like, and when she did I managed to change the subject. It's not modesty that I'm worried about, she has seen me naked on several occasions such as when I've been swimming. But I'm not sure if it would be healthy for her to watch me masturbate. However I don't want her to feel like she has done anything wrong just by being curious, so I avoided outright refusing her. I'm sure she's going to ask again, and I'm trying to figure out how exactly I'm going to handle it.