This story has had names changed for privacy
My sister who is five years younger than I am give or take a few years asked me how girls masturbate. I asked her why she didn't ask my other 22 year old sister who I know for a fact masturbates very regularly. She said my older sis wouldn't tell her because she was too young.
Just for kicks I told her of many different ways girls can masturbate. She liked the electric toothbrush idea best of all and she asked me if I could show her. Ok, no big deal, I showed her where to position it and then she turned it on. I got up to leave hearing her moan with pleasure.(she was nude and I was in my boxers only). She grabbed my hand and begged me to stay her first orgasm was great. Then she turns to me and says your turn. I didn't know what to do so I pulled down my pants and masturbated. We both cleaned each other up and she kissed me good night. Wwe still masturbate quite often in front of one and other, she is now 20 and I am 25.