Not Sure...Need More Science

You stand there not realizing what you were doing as your hand continued to jack your sisters cock. You were a bit freaked out but it was being drown out by the hunger for lust. Your head was full of thoughts of backing your ass onto her and using it as a fuck stick. bit you lip as you rubbed her against you ass . You felt start to throb in your hand as Gwen started to breath heavy. She doesn't really know what to do other than brace herself by putting a hand on you shoulder.

“ John you really need to stop that. You are making things worse. ” Gwen groans out. Gwen's balls start to sway and throb. She opens her legs a bit giving her cock more room to get pleasured.

“Oh am I?Oh no I think I'm making things better.” You say . You continue to give Gwen subtle tugs as you toy with her. She was breathing heavier and putting her forehead against the back of you head. She then took her and traced them down your body and gripped your hips

“John what are you doing Are you trying to get me off again?” Gwen says as she feels herself get closer to the edge. You started to tug a little faster. The soap that was on your hand before had given a nice velvet feel to you hand as you glided it up and down her lubricated dick. Her hand felt so full and swollen.

“I thought my name was Sara? Call me Sara cause it will help you not slip up in front of dad.” You didn't know who were. All you knew was that you didn't get the cum after your sister interrupted you so you wanted to have a little fun with her. “And no just like torturing you. You said things would be different as a guy so I'm showing you how it feels to be teased.' You just stand there squeezing her a bit more. You didn't know why but it felt wonderful and knew you wanted to keep going. You wanted to feel this cock bury itself inside of you. The scary thought was screaming inside you head drowning out reason.

“But if this is too much for you I will let go.” You tease stopping and slow down. You are still reaching behind you gripping her cock putting it in the worst position as it could have been. As Gwen's grip tightens she abruptly pulls you close sending her rock hard cock into you. Luckily she misses you soaking wet pussy and pushes itself between you thighs. Her shapely tits now mashing against your back as your ass presses into her pelvis. Her cock was now bumping into your clit sending crazy pleasure throughout your body. You started to go limp as your hands go to the wall in front of you, one fiddling with the water so it doesn't drown you. The pleasure Gwen was feeling before increase tenfold as she ground her teeth and bit her lip.

"Gwen oh fuck you feel so good against me like that." You gasp out. The words echo out in the bathroom as you try to stifle a scream. The bathroom was in a different part of the house other then your dad's bedroom but still you wanted to make sure. You grow wetter in her grasp as you start to rock back and forth. God what you wouldn't do to experience a cock. You shake your head in an effort to get those thoughts out of your head.

“Fuck you 'Sara'. You got me so danm turned on I can't even stand up straight. Fuck I think I need to cum again how is that possible." Gwen says still grinding into your back side. Her cock head continued to bumping into your clit and rubbing against your inner thighs. She started to grunt and slowly thrust into you.

"Oh shit!' You yelp as Gwen's cock pushes further between your legs. You look down to see her head and shaft poking out from between your thighs. Her long cock was so hard and putting so much pressure on you most sensitive areas. You tremble as your legs squeezed her cock and hold it against your clit. It was pulsing and you could feel you pussy juices leak all over her making her slick. Gwen started to rock back in forth sawing over your clit making you breath heavy. Look what curiosity got you....