Mom and dad were shopping one Saturday afternoon and me and my sister were inside because it was raining outside. Matter of factly she asked if I wanted to get naked and play doctor like we used to when we were little kids.
I couldn't believe it-- I had been wanting to see her without clothes since she started filling out two years ago.I told her sure and she said we should go to our rooms get undressed and meet in the kitchen 'cause it was close to the hall and if mom and dad came home we could get to our rooms faster.
I almost tore my clothes getting them off and ran to the kitchen so I'd be there first.I stood around waiting for her but she never showed up.About ten minutes later she came from the direction of the living room and she still had all her clothes on.There I was standing there naked with my sister standing in the doorway looking me over.
'I changed my mind,but since I backed out I owe you one.How about if I play with your cock for awhile.I want to see how big it gets.'
She didn't say anything else but walked over to where I was standing and touched just the head with her fingertips.I was semi-hard at the time and thats all it took for me to get an erection.As soon as I was hard she wrapped her hand around me and gently pulled a couple of times.At about the tenth stroke she cupped my balls with her other hand and I couldn't hold back any longer.Good thing she was standing off to the side a little or I would have sprayed all over her.She held me until I was completely done dripping,smiling the whole time.
'That was neat,now that I did you maybe one of these days you can do me.'
Well that was five years ago and she's leaving for college pretty soon and I'm still waiting.