Always wanted this to happen.
My sister and I are twins and ever since she started getting breasts my friends have been telling me that she is incredibly hot.
Well anyway, we had to share a room for a weekend because our grandparents were visiting and we didn't have an extra room. We were in her room and she had full bathroom in her room.
I was taking shower one night and jacking off like I usually do. I'm generally loud when I masturbate, but since my sister was in the room I had to keep it quite. She must've knocked on the bathroom door, but I didn't hear and she walked in on me jacking off. We have always been fairly close about our sexual encounters so she knew I jacked off, but had never seen me do it, so she must've been startled when she saw me stroking my penis. She didn't say anything and quickly left the room. She was back within ten seconds.
She was completely naked (always wanted to see her in her underwear, but this was even better) and she a vibrator in one hand and some lube in another. She turned around to switch one of the lights off and she had another surpirse...a butt plug already in her ass!
She hopped in the shower and told me that the movie could and that she had always wanted this to happen. I told her I did also. She made the first move by grabbing my ass and pulled me into her so that my hard cock was between her legs right under her pussy. I then grabbed her boob with one hand and backed and started rubbing her clit with the other. She started stroking my penis and moaned in unison.
I then asked if she wanted the vibrator in her and all she could do was nod her head. She took out the butt plug and sat down with her legs spread out wide. I kneeled down, switched the vibrator on, and inserted it into her soaking wet pussy. She screamed with delight as I washed off the butt plug and stuck into my own ass.
She then reached out to stroke my cock again. With a butt plug in me and my own sister jacking me off it only took a few minutes for me cum all over the place. Now I was free to work on her. I started sliding the vibrator in and out of her while flicking her clit. She said she was to cum and I went faster. She then let out an ear-shattering scream.
We stood up washed off and got out of the shower. My sister walked over to her phone and called her friend. She said she couldn't make it to the movie, but that her friend could come over if she wanted to. My sister hung up the phone, said her friend was coming over and pushed me on the bed and we started making out.
Ten minutes later we heard the doorbell ring and to our mom to answer the phone. Within 20 seconds the bedroom door opened and...TO BE CONTINUED