My sister

My sister was 21 in her 3 rd year of college home for Xmas. I was 19
Now my sister had no clue this was coming nor did I I always thought she was cute in a nerdy sort of way. She was just over 5 foot very skinny and as far as I know never had a boyfriend. So mom and dad were gone for the evening my sister had just gotten out of shower and had a robe on she came out to me and said she couldn’t get the water to shut off. So I go in and help her all it was is a loos handle but when she bent over to show me I saw her little tit pointed out and it put my hormones in over drive. I reach down and force the handle and get the water off she couldn’t leave unless I let her by me she looks up at me as I reach down in a quick motion pull her robe off her shoulders. I wasn’t even thinking she tried to pull away and said why did you do that.
I was honest I said you looked so cute standing there I wanted a full view. She stoped in her tracks and looked at me. Why would u want to see me naked standing there her tits were exposed robe still in my hand holding it off her shoulders .
I didn’t answer I just leaned down and took her nipple in my mouth. She didn’t stop me in fact she put her hands on my head and seemed to hold me too her chest. I pull her robe and let it drop to floor and start rubbing her clit with my fingers she tried to pull away and I held her with my other hand it happened so quickly I lifted her up and sat her on counter and was seemed like instantly my boner was out and in her. I was in overdrive shock really like a outer body experience. We ended up on floor when we were done all she said was she was sorry and she ran out of the room.